I was given a small Starter colony G violacea x lobata from a forum member. I planted it in pure sphagnum moss and placed it in a deep tub 1/2 filled with water at the back of my greenhouse. Within a couple of months it had spread to fill the pot and was flowering like mad (pictures are somewhere in the forum). I found it extremely easy, far easier than many terestrial Utrics but I found that it does need a higher temp in winter, anything too cool and the plant starts to sulk and look very sorry for itself.
Interestingly, my plants all went crazy and all the traps in the pot strarted to bud and produce new rossettes so I would imagine that given a wide enough pot, huge colonies could be built up rather quickly.