With Thermal Expansion now updated for 1.7.10 and added to Unstable, I've decided to give the pack another go. I haven't gotten far, but what I've seen shows real promise for 1.7 modpacks. I've had some fun trying to get Pneumaticraft seeds to plant without drifting off into space or shooting out into the ocean, collected some Botania mystic flowers (though have no idea yet what to do with them), and was pleasantly surprised to find some dense ores while mining. There are still some rough edges, like a bad texture on the tinkers' pattern chest and some oddness with the Baubles inventory button, but overall it's been quite playable so far.
What new mods/features coming with 1.7 do you think look the most fun?