I did an experiment a few years ago comparing the sound of 4 DAW's. I have got a great multitrack session that Roland gave me when I was working for them selling V Studios and it sounds stellar. With no plugins at all you get a stellar mix with just the right balance of fader settings.
(This multi is a serious lesson in musicianship and miking techniques!) I compared the sound of Pro Tools, Sonar, Studio One and Logic. I set the fader levels exactly on all four DAW's and pan laws the same and only panned L, C and R. I then rendered out the 4 mixes.
There was no difference between any of them. They all sounded identical. In fact so much so you can get a perfect null with any two of them. I also blind tested a room full of engineers and believe me no one was hearing any differences either.
The OP is also talking rubbish about Studio One 3 sounding thin. It does not. It sounds fabulous. End of story.
Once you start using plugins and things then all bets are off but in summing mode it is really hard to pick any DAW. I am sure Cubase would have tested fine too.
If the OP is getting thin poor sounding mixes it could be due to his own lack of experience. The end result in is your hands not the DAW. I teach sound engineering too and use Logic and ProTools a lot in that situation and at home I have got 6 DAW's actually.
(Only use one though manily) I am often moving the same material between them
(for private teaching purposes) and I am not hearing major differences anywhere.