I just got done looking at the SP101 and the LCR. They are both very nice revolvers, but I settled on the SP101.
The LCR: Nicest feeling revolver at the sales counter. Fit my hand perfectly. Nice light weight (12 oz) will make an excellent conceal carry gun. Shoots 38 spec +p (should be adequate for any self defense).
On the minus side: not the prettiest belle at the ball, Ruger has lately become famous for putting new product out that had to be recalled for one reason or another.
The SP101: been around for many years, very solid, reliable revolver that with minimum care will probably last longer than you. Can use 357 magnum as well as 38 Special and 38 Special +P, this gives you more options (having more options in never a bad thing), Nice compact package, easy to conceal, lots of fire power for such an easy concealable revolver.
On the minus side: 25 ounces (before you add any ammunition) compared to 12 ounces for the LCR.
The tipping point: I took both revolvers to the range. The LCR is a nice shooter, but with only 12 ounces you feel every ounce of recoil that a 38 spec+P round delivers. Not that it is not controllable (it is!) But if I am going to shoot this revolver a lot (I am), then the recoil will probably become annoying at the end of the day. The SP101 shoots like a much larger revolver. 38 spec and 38 spec+P rounds are quite comfortable. 357 mag does deliver some recoil, but it is quite controllable. The worst part of 357 mag is the noise; and there is nothing you can do about that. I can shoot this gun all day long.
I chose the SP101 and have a revolver that I may not want to pocket carry all day long, but IWB or OWB or Smart Carry (crotch holster) are no problem. The gun shoots very accurately for a 2-1/4" barrel snubby, looks great, and gives me the option of 38 spec, 38 spec+P or 357 mag rounds.
Do yourself a favor and shoot both revolvers before you make your decision. Either gun will work well.