I just picked up a 4" blued M/27 no dash, I already have a 4" M/629 no dash. I'm partial to pinned & recessed Smith & Wessons. I've had a few 5" N-frames, Skeeter Skelton was a big proponent of 5" barrels.
Skeeter Skelton influenced me to buy a 5" 27 and to have Ahlmans's shorten the barrel on a couple of 624s from 6.5" to 5". Sort of a Goldilocks thing, not too long, not too short, just right (for him). I carry in a cross-draw belt holster, so the longer barrel doesn't hang up like it might in a side carry belt holster.
I have a 3.5" 27, bought it 30 years ago, but have never gotten around to shooting it. Actor Dennis Farina carried a 3.5" 27 in his role as Detective Joe Fontana in the Law & Order TV series. Gun guys notice such things.