I am a good one to ask. I went shooting with a friend who has the 357 LCR. Shooting 38's out of it was NBD. 357's were spicy, but not painful. I liked the gun a lot. We are both tall guys with big hands, but we could control it easily.
A few weeks later my LGS had a used 38 +P LCR for a good price. I brought in a couple of pistols I didn't want anymore and traded for it. When I took it to the shooting range I was very surprised. I could not control it well enough to hit the side of a barn. It smacked my hand around like a rented mule. The little round spot on the back of the grip made my hand bleed after only 30 rounds or so.
The extra four ounces that the 357 weighs make a HUGE difference. I was flabbergasted that only four ounces could make such a big difference.
I asked some advice here on the board and was steered towards larger grips. I bought a set of the ones that normally go on the LCRx. Adding the longer grips solved my problem. When my friend and I went shooting again with both of the LCR's, we could both control either one of them just fine.
So my recommendation would be to go with the 357 version. If shooting 357's is not to your liking, just shoot 38's out of it. I personally found that the extremely light weight of the 38 version made it difficult and painful to shoot (though that might be due to me having very large hands).