I have to jump in on this because I love beardies
To answer your question an MVB is a mercury vapor bulb.It emits both heat and uvb at the same time and is great for beardies as they need both.
Now the pros:
They are funny,wonderful attentive little animals.They are for the most part extremely sociable towards humans so much so that I believe they actually not only crave but thrive off human attention.Yes the hardest part is getting the initial setup correct in order to ensure proper growth and development but after that things get alot easier.I cannot tell you how many times my little ones have made my family and I laugh hysterically.
Now the cons(if thats what you want to call it)
They need your attention.You cant throw them in the tank and ignore them.They do require vet care as with any other pet.You will fall in love,become their slave and eventually yes you will want more just like pringles
They are a commitment.They are not goldfish.They need you but trust me if your willing to give a little you will get ALOT in return.I call my beardies my scaly puppies because thats what they are.
Vicky