Bolt Man, you just had to say something didn't you...
I've been kickin' the idea of a 638 around for about a month now and your thread may knock me off the fence.

I already have a 649-3, which is the all stainless .357 mag version of the 638, that I feel is too heavy for pocket carry so I've been relying on my 642 for that role.

I really like the 649-3, other than the weight issue, which is why I've had my sights on the 638......

There are a lot of good ammo choices out there so it basically comes down to personal preference.
I tend to go with Buffalo Bore myself when it comes to self defense but also like the Speer Gold Dot 135 gr. "short barrel" round in the smaller, lighter J-Frames.