I have been nothing but pleased with this lens since I got it and it is the budget version too.
Looks like it’s well worth the price… beats my budget 75-300mm all to heck for sharp focus and color correction. Those UD elements make a big difference. No idea on humidity vs CA, but ow humidity usually means really transparent air. I’ve got the low humidity here, but the constant wind and turbulence normally puts the seeing into the mediocre category. It’s actually kind of neat to watch stars change color rapidly, but it doesn’t help much for imaging.