I was very happy on Celexa at 40mg for about 10 years, then went through a divorce and layoff and got bumped up to 60mg (!) for 2 years before it lost efficacy. There was a pretty significant improvement in the 40 mg vs 20 mg in my case. I almost forgot I had anxiety! The only downside I experienced through all those years was that I wasn't able to cry easily. It would take a really big build-up to finally get to tears. But that wasn't bothersome -- just the only side effect I noticed.
Thank you for the reply, the 20mg is working great just not where I want to be!!