I'm pretty new myself -- preparing for my 4th grow now -- but I've been trending down in size. I had been using hard pots that were a bit larger than five gal, but last time I added smaller fabric pots for comparison. (They were advertised as 5 gal, but really they seemed closer to 3 1/2.) I loved using them, and plant size/yield was just as good as the larger ones. Next time I will only use the fabric containers.
The thing is, the longer and bigger you go, the more unwieldy everything gets. Harder to keep a close eye on everything -- which is essential while you're still learning what to look for. By keeping to a modest schedule (e.g. 4 weeks grow plus 60 days or whatever your strains need for flowering) you're minimizing complications -- and you'll still get plenty of great quality bud. Don't fall for the hype that bigness equals quality. Bigness can be a pain in the ass.
I also don't think I've suffered by going straight from dixie cups to 5 gallons. I kind of tried to imagine root size while watering, so during the first couple of weeks after transplanting I gradually moved from watering less -- just around the plant -- to watering the whole pot. Seems to work well, but, as I say, I still have a lot to learn.
