Good question - well my goal is to develop into a solid MTTer and that in the end I'll be comfortable playing any size field. At the time I started this year, I've always felt I had a solid chance to cash in large large fields, but I think the highest I'd ever finished in a 1k+ player tourney was like 40th-50th. That's a lot of time invested with generally just doubling your buy-in when you cash. Not very good for your EV.
Because of my schedule, unless my job changes (which is a possibility in the not-so-distant future) I won't be able to ever play a high % of regular MTTs because of the amount of time you need to play them to the end. But eventually I do hope to be able to pick say Saturday night or Sunday night and have one night a week that I play a few of them each week, while during the other nights of the week doing 90s and 180s.