Thanks, the way my viv is set out, is that around the basking area there's different levels of branches/logs so he can go right up to it (obviously not touching) or he could bask up to, I would say 10-11 inches away from it.for a beardie I would say the tubes are better, I use tubes for my beardie but my frilly I find the MVBs better as they kick out a lot of heat and the frilly viv is 5' tall so it is needed but a beardie viv (not sure what yours is) is normally about 2' tall and the animals shouldnt really get closer than 12 inches from it or they may get eye problems
MVB is a far better bulb, is cheaper to run over all, and give out a far better UV quality.
the only issue with them is that because you cannot use a stat with them, they can rise the basking and ambiant temperature up far to high causing the viv to get hot and cook the occupant. As such you have to make sure there is more then adaquat ventialtion and that the bulb is high enough away not to burn. it's a job of monitoring temps constanly and altering the bulb height and ventilation accordingly. I have now started using these and they are fantastic. The UV out is amazing and they last for 2 years so are brill. They make the tubes look aweful when you comapre uv output.
Rember though that uv is only directed at the basking spot, so if the aniamall doesnt bask (too hot) they wont get any UV. Some people to like to add a UV tube to even out uv.