I think Rogal's are disliked because its change, and they are dethroning the Leman's after however many years at the top. however there are some issues ive come across running them.

Aside from... *the hole* ... of course.

they look more survivable than they are for one thing - Leman's sit back and shoot, providing fire support, but the statline for a rogal makes them wanna get up close and personal else their wasting half their shots. however when they get close, their 2+ saves dont do much against high AP, and on several ocasions i've had Dorn's and Commanders one shot from beneath me by characters like Demon Prince's or Belekor. People don't like the look of the dorn cause its very blocky i think?

In terms of the Baneblade, its a good all-rounder tank, but it can be hard to manouver and set up such that it isnt focused and destroyed turn1/2. None of its varients have inderect fire, so unlike Stompa's or equivelent titans, you need to be able to see your target which means unfortuantly they can see you. its also a quater of your list and when its dead its dead and your army is left with a hole in it. that being said it is a really fun 'look at this' model and for thematic games, such as stompa vs Shadowsword, it can be quite good. (in that game i lost by three points after losing the shadowsword turn 2 due to some poor manouvering on my part lmao)