Time Warp!!!
Then and now I still prefer my long throw.
Currently use a 25mm with a 5in BP and a 25gram pad to get it to run its smoothest.
With Makita PO5000C and even the MILLE, im more inclined to use my forced machines ( I have a forced 3in mini on the way!)
The short throw forced machines feel more comparable to the longthrows when talking balance..when you have correct pad weight and it being level on panel.
My assessment from 2015 to 2022 on machines
Overall, longthrow is the smoothest and typically finishes the best
Same goes for correction speed, typically the fastest.
But..
Hard paints, forced is better at than the longthrows
Medium hardness, longthrow takes it.
Soft paint, whichever finishes out better in the test spot.
As for machine imbalance.
Pad weight is a huge factor, more so when were talking about going from a 6in to a 5in or a 5in to a 3in
Best way to dial in machine balance is keep a lineup of new pads, 15 grams(LC thin pros) all the up to 45 grams(LC HDO or B&S Low Pros)
Free spin each on mad speed. Go with the smoothest.
You'll find there will be a few different weight pads that feel the same...say 25, 30 and 35 gram... Youll want to go with the lightest. Reason being is your pad will load up with product and make pad heavier. You got a margin of room to where the product buildup wont throw off your optimum balance..
Foam composition.can also affect balance while in the surface such was a really stiff pad like buff snd shine low pros...too stiff to contour so you may get pad bounce/wobble.
Only machines where pad weight tuning really doesnt make the machine smooth are your standard throws 8mm/9mm D/As and the 3401
But best route for those are heavy HDO or force pads for 3401 and LC thinpros for the standard throws.