Good ankle gun? I'm thinking of that in a Renegade Cozy partner inside my boot for work...

I have one,it's my hot weather pocket carry CCW.It is what it is,meaning short barrel w/short sight radius and not fun to plink with.Reliable like all smith's but be careful what you use to clean it with the finish will come off the alum frame.CLP (breakfree) is what most recommend and what I use.They are designed to be carried a lot and shot little ,save the Plus P ammo for carry only.

Edited to add-pick up some Bainchi Speed Strips,they are a great way to carry spare ammo.

So, 158 grain lead is good for practice?

I use my 637 for exactly that, an ankle rig.  I use a Desantis leather ankle holster and its a real treat to carry - took about 2 days to get used to but now I can carry it for 12 hours without even thinking its there.

Great, thanks!