This review is for the pool as a concert venue. If a band you want to see plays here, it's worth going. If not, venue is not a place I'd go to see something random (like I sometimes do with Red Rocks). You will be standing on concrete (unless you fork over big bucks for cabana level). It will be hot (even in October it was in the 90s late at night). If you're close to the stage you will be looking up as the stage is elevated. I came for Garbage's 20th anniversary tour and it was totally worth it.
Thoughts and tips:
Get the advanced entry passes if you want to be close.
If you want to see the show and don't care about being close, try to get a room with balcony overlooking the pool. You can chill without the crowd and see the show.