If you want to have some powerful, multihit attacks on the flank, I'd much rather have Rippers. They are significantly faster, and can dish out a ton of attacks, especially if you toaded said unit. S7 is rarely worth it against most things you want to flank, and let's face it, a main combat block wont get in a flank charge unless the enemy messed up somehow. That said, I have had some good results using Skroxigor units. The dwarf player I tried them against for the first time was rather surprised to get 6 S7 attacks thrown on his dwarf lord from those kroxigors. But I guess Dwarfs, Chaos, and similarly armoured armies (Lizardmen using saurus too, ironically) is their favoured matchups. Against elves, and undeads+skaven especially, they are just too inefficient. They want good AS targets, as well as T4/T5 targets, not T3 elves or humans with a 5+ AS. Might as well stick to Saurus for that.