Just some comments.
I note your WGDGPS 3.0 is in a clear Bottle? Mine, bought a few months ago came in a black bottle. Was yours a recent purchase?
I too have used Meg's M-21, WGDGPS 3.0, and even Meg's M-20. Have done two vehicles with WG, have gone through a bottle of M-21 over the past couple years, and back 15-17 years ago regularly used M-20, and in fact easily went through a full 12 bottle case of it on my vehicles, and others.
Always liked M-20, seemed to last longer than other Meg's products. M-21 seemed sort of similar to M-20, a different color and scent were the two most readily notable differences.
Longevity will be one key, as I have used virtually every Meg's OTC products over the years, and although many worked nice, one flaw I found with many of them from years back, was most wouldn't last, one car wash, and virtually there was no protection left. (Meg's may be better in this regard at current day)
Still, I would say none I've initially spoke of will fully protect against some nasties us car owners encounter, things such as bird bombs.
I've applied M-20 on a weekend once (on a new 1984 Silver Blue Trans Am I owned, had bird bombs land on the vehicle the following monday, and seen them almost permanently stain the paint.
That in general, none of these may protect as well as sealants like GTechniq EXO, CQuartz, Opti-Bond, and I reckon that's understandable, given the initial costs of these long lasting Sealants against other more common products available.
It would be interesting to see this thread updated some weeks-months down the road, to report back if any differences in longevity of these two products are noted? Mark
