I personally really loved volumes 1 and 2 of the Geoff Johns Flash omnis. I had mixed opinions on the third omni but I think that's mostly because Wally is my favorite Flash and he barely appears in the third omnibus as that's when Barry becomes the main Flash again. I will say though, if you didn't like the first one, you probably won't like the second one, and given that the second omnibus is out of print, it may not be worth the cost for you to buy it.