The new trigger is also on some later MKIIs. If the back of the trigger is hollow it is the new trigger. Ruger will fit the new trigger to a MKII if you want. The only other difference is the Hawkeye has a matte blue and the MKIIs are gloss blue.
I bought a Hawkeye Compact in 7mm-08 and fired it last weekend for the first time. After 10 "break-in" shots (cleaned the barrel between each), I started getting 1 1/2" groups at 100 yds with Remington factory loads. For a rifle so light, I find the accuracy to be really good.
The trigger has a tiny bit of creep and breaks at 4 1/2 lbs. A bit heavy for my taste. I imagine it will get better with use.
The butt pad has changed as well. It is back to red on wood M77 Hawkeye's and that goes for the Compact as well. The Hawkeye is as accurate as any of my other M77's.
The triggers vary on the new Hawkeyes but overall it is better. Usually a lighter spring will fix any stiffness you may feel if you don't like the stock one. Creep is minimal and I don't feel creep when shooting in the field anyway, mostly at the bench.
The Compact has a short LOP but you probably felt that. You will probably have to shop for a MKII if you want one now buy the Hawkeye.
I've got the wood and matte finish compact hawkeye in 7.62x39. With Wolf Ammo it shoots about 3" groups at 100 yards off the bench. With golden tiger the groups are 1.25". With my handloads just under an inch. These are two 4 shot groups 8 rounds total. Love this handy little rifle.