I've done both ways, and since I've tried foiling (steam pans with a tent for me), I like the more tender texture it can yield. Depending on how tender I want it, will determine the foiled cook time. Then, firm it up on open cook grates again, just to give a bit stiffer exterior of the meat. I love this method for ribs and roasts (pork and beef).
I almost always use wet smoke, and I never thought that foiling would make much difference...I had to prove it to myself. I highly recommend it.
Good smokes to ya!
Eric