With regards to full underlugs:
Practically speaking, I'm a fan.
My 3 "working guns" are a 4" 617-8, a 6" 586-3, and a 6.5" 629-4 Classic DX. All with, of course , full underlugs and also Hogue Monogrips for uniformity in my hand. Plus, I keep the purty (and slightly less practical for me) original wood grips in the boxes for when I might wanna dress 'em up.
I think a full underlug improves the balance and solid feeling to my "working" guns. IMO the underlugs do make them easier to shoot in terms of recoil (617 notwithstanding. WHAT recoil?)
I don't often carry them out in the world, however. My carry Smiths are devoid of the underlugs in the interest of weight. That said, both the L- or N-frames ride just fine in my Bianchi X-15 when I'm out back in the bush and wet weather warrants carrying inside a pair of Carhartts. (Actually, I'm looking for a stainless beater for everyday carry. My carry-size Smiths are all in 95-plus % and from the early '60's with box, docs, and case candy. I'm gettin' a bit squirrelly about them spending so much time getting holster wear and whatever bad stuff could happen to them.)
The Python and its fellow reptilians are, in my world, kinda like Ferraris. If you can afford the ride, you better be able to afford the maintenance too, because there's gonna be lots of it.
The Smiths on the other hand, are akin to a Willys MB jeep, only as tuned and fitted out a Willys as is possible for one to be. Dead reliable, solid as a Sherman, but also a fine piece of machinery and not only a joy to drive, but loves to be driven.
After all that, I do have a fondness for a Colt-made gun due to primarily the history but also because it's certainly not a terribly-made piece of gear, it's just not the cherry on my own personal cake. If I MUST have the experience of shooting a Colt (which can be a nice change of pace), I have a 1907 Police Positive Special in unbelievable condition that fills the bill. Not a serpent, I admit, but close enough to shut me up.