7 Springs is much larger and more crowded, but if you ski on the back side of the mtn, the lines aren't too bad. 7 Springs is more of a resort than Wisp and there is a lot more to do.
The accomodations at Wisp are more modest, but cheaper. Wisp is less crowded, but there is less to do after skiing. They have a really nice bar though, with pretty good bar food.
Both will probably have similar snow cover, but 7 Springs does a better job grooming.
If crowds are your main concern, then I would go to Wisp. Have Fun!
A thing to remember about Wisp is that even though it doesn't have a lot of on location stuff to do, you do have the entire area of Deep Creek Lake to explore right there where there is TONS to do. GO Karts, mini golf, decent food, and nearby Oakland has movie theaters and such.