So I have a favorite build of mine that involves Boba & Kath, and I finally got to convert it to scum last night with the release of 5.2 vassal.
I don't want to go into details of my squad or the game itself, just focus on the my impressions of the new abilities scum boba & kath have.
Boba
Ability did come into play several rounds. On defense I don't think I got a single re-roll to turn to an evade, so that was disappointing, but I know that was below average and it's definitely a powerful tool, especially when multiple ships are shooting at you. Offense I got better use from, although I have predator on Boba, so there was at least one occasion where I only needed the one reroll from predator so his ability wasn't needed. If you don't get blocked at range 1 (and that can be tricky) I could easily see taking an evade usually and doing a target lock basically between predator and his ability.
Kath
Oh Scum Kath, how I love thee! It took awhile before I got to use her ability for the first time, but I had two extremely good attacks with it, both at range 1. The first I rolled 4 crits and a hit after all modifications. Only the hit was evaded so I did some crazy damage, although my opponent got pretty lucky overall with the crits they received. The other attack I got a crit and 4 hits after all modifications. Running away from an opponent in general with Kath is much more satisfying now knowing you always have that extra attack die.
So overall I think my squad will be getting a pretty good boost by the new abilities for both of these pilots. My only regret is that I often used rebel captive on one of them, and can't anymore now with scum.