I played another couple of games today, though didn't take pictures for batreps. I'm basically running the same list at 1k-1.5k points every time, something like:
Big Mek on Bike with KFF, Killsaw
Weirdboy
30 Shoota Boyz, Nob with Klaw -> On foot
(10 Slugga Boyz, Nob with Klaw or Big choppa -> In Trukk) * 3
Big Gunz Kannons
A few Warbikers
The basic idea is to Da Jump the foot squad for a chance at turn 1 assault, and run up the trukks and the warbikers under the KFF for a turn 2 Assault if possible.
Almost always, it's a question of whether or not they can crack open the trukks and kill the stuff inside during the 1 or 2 turns of shooting they get before assault, as well as how well the 30-man foot squad does at shooting and assaulting. I have had a LOT of trouble with a fully mechanized marines list. I've pulled off wins against mech chaos and an admech shooty army.
I tried running some nobz in a trukk once and it didn't go so well; the other guy was able to focus it down and kill the nobz inside in one turn of shooting. I think the "lots of trukks with like 69-point 10-man boyz+nob squads with big choppa" strat has been... okay. Boyz are really good in assault, but getting there is a problem.
I was previously running the 30-strong unit with slugga boyz, but because it completely steamrolled anything it charged, I changed it to shoota boyz, so it could shoot at something else then charge and still steamroll. Also, in the trukks I now run slugga boyz, but i'm not sure it's a great idea. I feel like so much is just "how many boyz make it to assault intact" and "how well can you consolidate into units and force them to Fall Back so they can't shoot"
Also, it seems like KFF Big Mek is an essential unit if you have many trukks.