the func_group yea is an entity that they didn't null/clear out in the code.
q3 had that problem too when it first came out; lots of spam "func_group doesn't have a spawn function" etc; it'll probably be fixed.
and no they never have had a good reason to change things. ever. "I wanted it this way" is what excuse i always got. if I had time i'd create a fork off of 1.5 like i did for 1.3 and make my own shit work, i just have no patience and really like the way that doom radiant works (even with it's memory leaks).
there are so many bugs that they deemed features that I don't even bother posting them anymore.
ok like fucking HIDE CAULK. that is supposed to HIDE ALL CAULK surfaces. it's that simple. in 1.5 they don't hide caulk unless the whole brush is caulk. now it may be in 1.5 that maybe/because the primary face isn't caulk so it's not hidden, and if that's the case then that was a bug that was fixed then "snuck back in" in 1.5. Sometimes you just need caulk faces overlapping textured faces; there's no reason not to. it's a mapping style.
at least radiant works like it should.
if you look at the original radiant manual you'll see that about 70% of the functionality/instructions are just plain wrong. you don't need a changelog, you just need to look at the manual and take out (at random) 3/4 of it and there ya go: that's what is broken.
