He does like to "come in" a bit quick on occasion, but on the whole I've found him fairly judicous about it.
When we lost to quins, Shenton's defensinve effort was hailed as one of the only plus points.
IMO he's very difficult to get around, but has missed some absolute shocking misses in contact - Hoffman being one and there was another i remeber on Gilmour.
Gaskell isn't a bad tackler, but he seems to either give his man way to much space or be ball watching and almost looks suprised when the oppo centre gets possession. The HKR home game was the first clear example, and then Carmont exposed him aswell. Even then he doesn't always miss the tackle, but the half break is enough to put us way on the back foot.