On straight tracks, both Assegai and Harimau are at a clear disadvantage compared to Icaras. But for really technical tracks, I think Harimau is very good for TT.
'Like an understeering Assegai' - that's a very good description, actually!

I always found Harimau more pinpoint than AG-Sys, but you have definitely more playtime with Harimau, so your description is more accurate for sure.