what re all the walls like?
Hoo, large question, there are lots.
Thalkirchen: *is* the DAV-owned one. Huge but nevertheless can get very busy in the evening. But, because huge, also quite varied. Good for both routes and bouldering (the old boulder room is better than the new one)
Boulderwelt: good modern bouldering wall
Heaven's Gate: near boulderwelt. Quirky but rather dated & limited. Semi-ok bouldering.
Gilching: also DAV. A little way out of town but reachable by S-Bahn. Smaller than Thalkirchen, laid back. Spectacularly soft grading, so good for an ego boost.
High East: also a bit out of town but right by an S-bahn station. Not that big and gets busy, but generally the best route setting. Limited bouldering.
... and there are other, smaller ones that are really only of interest to locals
all well worth a visit, although I personally don't rate HG
There's also Baierbrunn. Small, rather odd horribly polished conglomerate bouldering area near the river, near an S-Bahn station. Toni Lamprecht likes it, according to an interview I read recently, so there must be more to it than meets the eye