Nope. They share the same channel. Hmm, I'm looking at the Triple XXX as well. As far as clean tone goes its better than 5150.
But personally, getting the 5150 head might be unwise if you're living in an apartment. You can't crank the tubes at all. Even if you get an attenuator, it might still be too loud. 5150 head + 4 x 12 + attenuator can easily exceed 2.5k I think.