I am a module girl and have excellent success with it. For me, it is a time issue. Between 2 allotments, garden, house, 2.5 kids, Ava, family, etc and so on, etc..... time is always precious. I find module or pot grown plants can be left to their own devices until I am ready to plant out - celery, celeriac, lettuce yesterday for example. Pushed out with a short piece of bamboo, no root disturbance, strong little plants plonked straight into their little hole. I think it is just a case of whatever suits you - sone people have the time, and are light fingered enough to prick out, others suit module life.