I am betting that for the same barrel length, the 69 will be trimmer and lighter than the GP, so I do not expect a size or weight penalty for the added .44 magnum capability of the 69. I guess that is an interesting question for those solely thinking of self-defense: if the 69 and the GP were both offered in the same 3" barrel length and offered comparable configurations (sights, barrel profile, etc) but the 69 were lighter and trimmer than the GP, would you still prefer the GP over the 69?
Regarding intended use, they both will serve admirably in self-defense roles against humans, so there is no knock on the 69 there. However, the 69 will serve pretty well against anything in North America, regardless of leg-count. Again, can't see it as a detriment.
I am also guessing a lot of people talking about the recoil of .44 magnum in the L-frame and GP package have not shot a 69 or similar package. It is a handful, but it isn't probably as bad as one might imagine. It isn't a 329PD. It is also interesting how the smaller frame handles recoil compared to a N-frame with less muzzle rise and more of an into-the-palm recoil. I'd recommend trying one before writing it off. I also have a 5-shot Freedom Arms 97 in .45 Colt with a similar weight and same barrel length, and with similar .44-mag-like performing loads, the 69 is much more comfortable than the FA which really surprises me because I prefer a Bisley over a 29. With a 300gr load, I don't even want anything to do with the FA, but with the 69, surprisingly not that bad.
Just some observations based on actual experience shooting the smaller 5-shot mags.
Having shot over 7,000 rnds thru 2 M69s and 25,000+ two FA97 .45 Colts (a 3 1/2" and 4 1/4"FA97), my experiences are the same as those of eldon519. I had a S&W 696. It was replaced with the M69 with no regrets.
I understand personal preferences and if yours is the new GP 44 special, then go for it and enjoy.
FWIW,
Paul