First off, I need to caveat this with I am new to this. This is my first year and I have had my fair share of issues. That being said, in my *extremely limited* experience, the grass is not always greener. I am guessing you did not have the yield you were looking for/a number of problems/space for the growing list of desires in the ground. I started this season with no real idea of what I was doing and after spending time on other gardening websites jumped into raised beds. After the first month or two with no growth, curled leaves, leaf loss, and other issues I came across this forum.
The consensus was that the majority of growers were using pots and felt it was easier to control all aspects of the plants. You could feed, water, and give light to each plant differently hell, if there is an issue such as disease or something you can just move the plant instead of having to dig it up. Guys like Silver Surfer has a ridiculous in ground farm and AJ has it all, a T Scorp field (which is an understatement) and the backyard that im sure rivals Neil from THSC, so no matter what you choose there are both types of mentors here. I read a bunch of posts and probably pissed a few off with the amount of questions and redundant threads I posted.
I heard about the illusive PROMIX BX and how it is "the best". I didnt see some of the shortcomings, or there really wasnt much out on the problems. But I got in my car and drove to ever nursery in a 50 mile radius until I found some, got enough to fill all the pots that I was going to rip my plants out of my beds and stick in, and I was off. Everything looked great, until the rain came. We had 2 days of on and off downpour and 50% of my plants had problems from it. The PROMIX just wouldnt drain. I didnt pack it, I let the first watering do that, I had plenty of drainage holes, the mix IMHO has trouble draining. So after this rain, the plants in the pots looked like wet noodles, yellow wet noodles, and the plants in the beds were a little small, but green and still setting fruit.
I am sure that if I would have done some more digging and read into everyone's mixes, I would have discovered that some add a handful or 2 of pearlite to lighten the mix, but I just read everywhere that PROMIX was the best, so in my noob attempt to get harvests like the best I had to have the best.
The moral to this admittedly too long post is understand that a bag of soil is not going to grow peppers, you are. Think about it, nature doesn't have PROMIX, and all these peppers presumably grow or have grown in nature. If you need some visual proof just look at SS or AJ's threads and im sure that neither the 3000 sqft farm SS has or the T Scorp amusement park aren't PROMIX. If you chooses to spend a fortune on it, be careful and mix it with pearlite. I would say like 3 to .5 and go from there. Also DO NOT PUSH ON THE MIX to set the plants in. When you water them in, the mix will compact and stay that way. But if you have the space to throw even a few plants in the ground, I would go with it and just apply what you have learned this season and from the pros.
My .02 (or actually .06 or .07)
Good Luck!
Matt