I played a game using the playtest changes last night against Ryan (Man of Kent).

My 3k list was:
Thunderhawk
Tactical + Chaplain + CC Dreadnought (in Thunderhawk)
Tactical + Land Raider
Predator Anhilators + Hunter
Predator Destructors + Hunter
Vindicator
Assault + Vindicator
Land Speeders
Land Speeder Tornados + 1 Typhoon
Terminators
Bikes + 1 Attack Bike

Ryan was using a Barran Siege list with 14 formations. From memory: 2 howitzer formations, a Reg HQ with added griffons, 2 AA formations, 2 Shadowswords, a Ragnorok formation, 2 light scout tank formations and 3-4 infantry formations. 2 sets of trenches and bunkers/razorwire.

I enjoyed the game but didn't do that well. I lost 3-1 and didn't have much left alive my the end of the game, though I was happy my carved wooden Rhinocerous which Ryan previously came across on the street while we were out walking (proxying a Rhino) made it out alive. In both of the first two turns my Thunderhawk tried to come down on a retain to assault and failed both times, damn thing. I could possibly have played more tactically towards the end for victory goals, but I knew I'd lost and played them heroically, trying against all the odds to kill his dug in BTS/HQ in the corner (and dieing/fleeing).

Few thoughts:

Overall the list seemed good, though I've not played much in a long while, so wasn't playing as well as Ryan.

After trying out 5 Vindicators I really like them. They reliably killed and hurt trench/bunker dug-in formations my Predator Destructors and Land Speeder Tornados struggled with. Walker helped too. I'll have to see how they do in other games, but so far I like them, including adding 1 to an Assault formation.

Now that the Tornada is free (as it should be) the Typhoon really doesn't feel worth the extra 25 points. Land Speeders are fast and often garrisoning forward so they'll be able to get in 30cm easily enough and they're extra AP3+ isn't that big a boost. I reckon a good price would be 15 points or 10 points (like Epic-UK went for) but this latter feels a little too low for me.