get the roland cube.30s good.15's too small.its good.comes with alot of effects and stuff which u can play around with.but the problem is that the volume knobs reali sensitive.A little tweak of it and the volume changes drastically.either too loud or too soft.thats the problem with all rolands actually.
Have you considered the Marshall MS-2 Microstack II?
It's basically an MG-15R but with a separate head and 2x10" speakers in 2 closed-back cabinets - better than the regular MG15R due to enhanced bass from the closed-backs. Plus, u can tell your friends you have a Marshall stack in your bedroom!
The cube 15 is more than enough for home practise, if that's what you are getting it for.
I used to have a cube 15, and the volume knob hardly passes '6'.
But if you are getting pedals/multi efxs, then the in-built effects in the cube 15 would be kind of redundant, though they are pretty good for the price you are paying.
line 6 spider 2 15w or 30w is worth considering if you want a good built in efx amp, cleans isnt as good as marshall or vox but the other channels are pretty good, remember to try the amps first b4 making up your mind.