Yes, either one will sound better. I personally prefer the M300 for at least 3 reasons:
1. Digital out, which means it can be used as a standalone A-D convertor
2. balanced analog outs
3. M-300's owner's manual is waaay easier to understand. Just do what I did, Go to GC, and make them open both boxes, and hand you the manuals. Then read them, and think about it.
Here is one caveat, though. The Lexicon and TC Electronics reverbs simply have a signature sound, and it is there, even in the cheap units. If you just prefer the Lexicon sound, all of the above will make no difference.
On the commercial project I just finished, very little FX of any kind was used in tracking, basically just electric guitar. Everything else was tracked dry, and FX added in mixing and mastering. But what FX we did use in tracking was all done with one M300, and the results were excellent. A number of tracks were run through the M300 just for A-D conversion, with all effects bypassed, and then into
a Roland VS1824CD, because the M300's A-D conversion is superior to the Roland's! For $200, what's not to like?-Richie