I've only been doing ribs for about a year now so I'm definitely not an expert.
I too have experienced the same issue as you when using either the 3-2-1 or 2-2-1. Sometimes they came out really well, other time they were pretty bad.
After tons of reading about times, foil vs. no foil, temps, etc. I decided to start doing my ribs with no foil and temps around 250-275. Since then, they've all come out great.
What I learned after reading is that ribs are kind of inconsistent. 2-2-1 at 225 may not always be the best time and temp for a particular rack. So now that I don't foil, I don't stress over how much time I need to spend in each phase. Just put them on and relax. I don't even open the lid until about the 3 hour mark. I check them using the bend method and toothpicks. When I think they are almost done, then I paint them with some sauce for the last 30 mins or so. My cook times average 4-6 hours.
One poster said it best, ribs take as long as ribs take.
Good luck.