Sorry that I closed the first post before getting it on the forum.
Back in February, I faced the same decision as you.
My wife had gotten her old Pathfinder rear-ended, and after looking at how minor the damage was on her car, and the fact that the 2011 Xterra that hit her was a total loss, she quickly decided that she didn't want a new vehicle, she wanted us to fix the one she had. At 24 years old, and almost 150,000 miles on the clock, it was tired. But, I agreed to try to get it fixed up for her, and started to look around. And, don't think I was being cheap. I've tried to replace that truck on numerous occasions over the years, and she just wanted to keep it. I even got a BMW X5, fully assuming that once she drove it, I'd have to go get another car. Didn't happen.
As I was doing my research, I found Autogeek, and spent a few weeks just studying all the information on this site. For the prior 30 years, I'd been perfectly happy with my 10" orbital polisher, and a supply of Liquid Glass.
Discovered 3 kinds of polishers, the DAs, the Flex forced rotation DA (3401), and the rotaries. The Rupes was available, but there weren't any reviews yet of that product.
I recognized what is referred to around here as "the flavor of the month" mentality, so I went back several years to see what had happened as products were announced, and the reviews began. Seemed like everyone loves a new product, and lots of new users buy it, and they are posting how wonderful it is, because that's what they have experience with. None of the issues get posted until something else comes along. When the Rupes was announced, suddenly there were lots of issues with the reverse orbit, with the units jumping by themselves, etc.
I discovered many people had bought the Porter Cable, the Griot, the Meguiar, and the "lowly" Harbor Freight units. Many of those posters wished they had stepped up to the Flex 3401, but weren't going to spend any more money.
I also read as people (not pros) expressed fear at the rotary polishers.
Personally, I don't like to have to keep re-buying the same technology again and again. I, like you, wanted one machine that I would be satisfied with for a long time.
Being a little analytical (actually, it's my career), I decided not to look at the decision as Door #1, Door #2, Door #3. If I compared two at a time, I could reach a logical decision.
I also recognized that I could probably accomplish any task with any of the 3 alternatives, it was just a question of how long it would take. I don't have any health issues that would preclude any of the options.
First comparison was DA to the Flex Orbital Polisher (DA with forced rotation). I quickly decided that if I purchased a standard DA, that I would almost immediately want to graduate to the Flex. The forced rotation was a big issue in my mind. It would keep going through anything, where the DAs would just "jiggle" when the task got a little harder. Advantage Flex 3401.
Second comparison was the Flex 3401 to either the Flex PE14-2-150 or the Makita 9227C. Since I wasn't going to do this on a professional level, I decided that my risks were lower with the Flex DA. I was somewhat afraid of burning the paint as well. Advantage Flex 3401.
Then, I started reading about the new Rupes unit. I concluded that the Rupes was another member of the DA family, without the forced rotation that helped me to decide on the Flex in the first place. Since there weren't any reviews yet, I could only judge based on the specifications of the unit. Decision over.
Purchased the Flex 3401, and started on my work car, which is a 2008 PT Cruiser in "cool vanilla". Wasn't all that concerned if I made an error. But, it was easy to use the Flex, and I didn't make any errors. The only issue I found was that since I had bought the kit with 6.5" CCS pads, there were spots that weren't easy to polish. But, the car looked beautiful when I was done polishing. Covered it with Wolfgang Deep Gloss Paint Sealant.
One issue I worried about was the comments that the Flex seemed to orbit in reverse. Watched myself polish by hand, and sure enough, I was polishing counter-clockwise and always had. Conclusion from this was that people got used to the orbit of the DAs, and this felt backwards to them. Having never used one, the Flex seemed like it worked like I did. I liked that idea.
We got the Pathfinder back from the shop, and I started to work on it. Fresh paint, as opposed to the thin, hard paint of the PT Cruiser. Again, no issues. I used Menzerna SI1500, followed by SF4500, and the truck looks magnificent from every angle, except for a few trim pieces that were still on backorder. They were so dried out from 24 years in the desert that they just broke apart when I tried to remove them.
So, happy with my purchase, and no desire to switch to anything else.
Watched the reviews of the Rupes. First reviews were glowing. BTW, as much as I learned from Mike Phillips, I mostly disregarded his product reviews. Why? Because his job is to present every product in favorable terms. They want to sell all of the products, so don't expect a slam on anything they carry. But, as time went by, he opened up a little, and reading between the lines I can tell that he likes the Flex 3401 just a little more than everything else.
As time has gone on, the reviews, while positive, haven't retained their early, be all end all flavor.
People had trouble on side panels, curved panels, etc. with the unit going into "jiggle" mode just like the other DAs. Someone came up with the "washer mod" to keep the Rupes spinning when it wanted to stop. Rupes says that negates the built in design of their product.
Here's some photos. I wasn't experienced enough at the beginning to take before and after shots.
First, the PT Cruiser practice vehicle
In addition to the SI1500, and the SF4500, I did part of the vehicle with FG1000, to see the results of using a compound. Still, no problems anywhere.
Here's the Pathfinder before it's restoration
Bumper already replaced, but rear of back quarter panel crunched
Another view - key scratches, chemical spill on hood, and deep burns in the fender from a battery blowing up years ago.
After lots of re-paint, I used the SI1500 followed by the SF4500. Then, a coat of Wolfgang Deep Gloss Paint Sealant.
BTW, I did break down and buy a rotary. It's a $40 special from Harbor Freight. That's for doing things like marble countertops, sinks, showers, etc. Won't risk my 3401 on those tasks, but figured that I could learn to use the rotary on some junk panels.
So, will I buy a Flex PE14-2-150 someday? Probably. Just to have it. Do I need it? No way I could justify that purchase based on need. I already have what I need.
I did add the Lake Country dual backing system, so that I could use smaller pads on the curves of the PT Cruiser. I got the 5" hybrid pads, as that's the wisdom of this forum. I like that setup a lot, and will use it when it's time for another pass on the PT Cruiser. I liked the hybrid pads so much, that I may also get the 6.5" version for the next round on the Pathfinder.
My wife got an old vehicle restored that she is once again proud to drive. She gets a lot of attention, and questions from people in parking lots about how such an old vehicle can look that good, as they are trying to make the same repair or replace decision.
Jim