The knee-jerk reaction is to say "old 2 channel amps sound better" but it depends on what you need. I had an older two channel Dual Rec, the clean sort of sucked, but the distortion channels sounded really good at lower volumes (as well as louder) the switching was very basic.
The newer Rectifiers (i.e. 3 channels) have much better features (IMO) that are VERY useful, esp. for someone who plays live. If you don't play live, or play out much, then the newer rectos would be a bad choice since they don't really come into their own until they are in the band mix and higher volume.
I've had my 3 channel triple rec for years now, and I'd never get rid of it. I love having three channels, switchable loop and 'solo' function. And, it sounds like a beast live and loud. And (lots of ands) they are relatively cheap and (for me anyway) 100% reliable. I run my triple hours each week at high volumes and I've nothing to it but change the power tubes a couple of times...not even because it sounded bad, just because I thought I should!