Both tents have a lot going for them. The Contrail is roomier. The Sublite is more stable. The Sublite sheds water better, but it has a smallish vestibule. (My Sublite, version 1, has no vestibule at all.) The Contrail has that big, flat surface and a simple one-hiking-pole setup, which are good things in good weather. The Sublite is much better in the wind because of the two hiking poles and the steep angles of the side walls.
The Sublite is easier to get in and out of and it sheds snow more easily because of the steep walls, but the steep walls make for less usable room compared to the Contrail.
If you're going for stability and 3+ season use, I'd go with the Sublite. If you might occasionally entertain a sleeping companion or you don't plan ever to use the tent in light snow, I'd go with the Contrail.
During summer, I always take the Contrail. When there's a chance for bad weather in the shoulder seasons, I always take the Sublite.
I love them both, and wouldn't part with either -- unless, of course I can find the cash to buy the new Sublite Sil 2010 to replace my older version. Hey, Henry! If you're looking for a beta tester, I'm your guy!