I waited for ages for a small upgrade but girlfriend was putting her foot down, then we had a new baby 2 weeks ago and she hinted at me getting a new tank!!! I was shocked but then realised she wanted a new pushchair instead of previous one from 1st daughter. I agreed readily and now have my 180 litre coming next week. Quite a step-up from a 49-55 litre I have at the minute. I can now get more cories and some plecs and really get going. Bank balance might take a bit of bashing but not to worry, you can't take money with you!!!
So to answer the question, I am over the moon with the tank I have coming and daren't think about anything bigger because g/f would kill me!!!