I consider "Street Survivors" more of a leap forward than a comeback, but I wholeheartedly agree -- the inclusion of Gaines (indeed, the entire lineup, at that point) had established Skynyrd as arguably the best band in America, if not on the planet.
Now they are a wimper of what they once were having only Gary Rossington and Billy Powell. Back in 79 or 80 I think I had the opportunity to see The Rossington Collins Band in Ft. Worth in a small venue. The 1st Rossington Collins album was excellent and showed that the band were more than just Ronnie Van Zant though both brothers pale in comparison. (Johnnie and Donnie). Somewhere along the line they formed the Allen Collins Band and put out one album which I thought was excellent. After that everything I've heard from them has been sub-par.