5w vs 15w guitar amp for studio?

I'd like to buy either the Marshall DSL5C or DSL15C for recording rock/electric guitar in studio. I know I need a lower watt amp in order to crank it up to get that full overdrive sound. An even higher watt amp would make the guitarist's ears bleed that loud, so I don't want that.. but I do want him/her to be rocking. And I don't want the amp in a closet.. I want the guitars to be next to it in case they want to get some feedback for effect.



So, is the 5w the way to go, or is it too "micro" to get that full Marshall sound to track? Or is the 15w the best "size"? Or is it too loud to be near when cranked for overdrive?



Thanks!

5w vs 15w guitar amp for studio?