First of all, congratulations on your 400K milestone on YoYo@Home, Peter!
I have all 3 quads working again and crunching up a storm on YoYo. I will stay there until the milestone is reached.
I think that Sztaki is possibly on its way down the archiving road. Tom Philippart and I and a cast of thousands have made multiple requests to Sztaki to update the OS identifiers so we can crunch there. Their lack of response is a sign of indifference, which is an early sign of failure. It will probably go the way of 3x+1 and SHA Collision. If we get the 1M milestone this month, we would lock it into our stats and would never need to crunch it again.
Which is a pity because Sztaki was the first project I crunched after SETI. I'll miss it.
ABC@Home is one I think we can reach if we really try!
Enigma doesn't play well with my comps, so I won't be able to help there.
I agree that Intelligence Realm can wait for some other challenge.
EDIT: A second thought on Sztaki-- because the admins are indifferent to the crunchers, they are probably indifferent to the science. Any thing we do will only be for the credits and may be worthless for the science. And worthless for our main reason for doing this stuff!