I find Lend Lease Assault to be one of the best UKF commanders because it fills so many holes in their lineup. Aggressive infantry. A T0 mobile mortar to fight garrisons or HMG 42s. A light AI vehicle. A cost effective medium AT vehicle to counter medium tanks without having to get a very expensive Firefly.
Crew Repairs comes in handy in the late game, although I wouldn't mind seeing it replaced with something with a bit more punch. Sure, the abilities aren't as shiny or exciting as Tiger Aces or big offmaps but they are very effective, and ultimately I do think the commander is already very good and useful.
I find this commander really fun to play on 1s, weak on 2s and uneffective on higher mode. Finally Brits has agressive commander with infantry that performs diffrently than basic tommies to allow use diffrent strat. Thing is that it won't work on teamgames where in most cases off map or skill planes are needed. Of course if crew repairs were replaced by some sort of delicate off map then commander would be more open to other gamemodes. But again you can't have everything, all commanders should have weakness. Anyway, people underestimated this commander which is a fresh breath to the faction. Yes, maybe 4 Tommie spam is stronger but this is definitely more fun.
It also suprise me that people in teamgames complain about early Tigers. Unit isn't cheap - it costs 230 fuel and it's locked behind T4. Players who rush for Tiger don't get any sort of medium tank meantime. So If you cannot build in that time Jakson, Firefly or a SU85 then apparently you doing something wrong or simply it isn't an even game.