Welcome to the forums!
Question about Logic sounding better than Ableton based on what you've read... Were people saying that Logic's stock/included sounds are better than Albeton's? Or was it commentary about overall sound quality? The reason I ask is because comments about sound quality can refer to the sounds that come stock/included with a program, or, it can mean the overall sound quality of your mix once you're done with it.
There's even a third factor, and that's what kind of audio interface you're using (direct out of your Mac or a 3rd party interface like an MBox or Apogee or MOTU, etc.)
So if you could post back with some more details we can probably give you some opinions.
But all that aside, I don't think that a DAW itself has an influence on the sound so much as how it works to suit the way you produce. The only time I've experienced a difference is when programming drum tracks on MPC compared to Logic and other DAWs. The MPC definitely has a vibe to it in terms of timing feel, and that's why people have looked for ways to get Logic to add that same feel (it is possible, details if you wannem).
Anyway, looking forward to what you have to say about the sound quality thing, and also about the way you produce. Are you making your own beats or using samples? Stuff like that...