Hi, it totally all depends on your preference IMO. UTH's have to go on the side or back which makes you lose a lot of heat, I use these and have to put 2 on for the winter to keep it at 82F. I have a 30-40 on the back and a small 10-20 on the end, and they are on the same end, and I had to also build a 3 sided box around it. With lights or a CHE you have to deal with the humidity but if you have some kind of fogger system that shouldn't be a problem. In my opinion they both have there pains so it all depends on how much you want to fiddle with stuff to get the enclosure at the right temps and humidity, a hygrotherm will help a lot if you have one. Oh and if you choose to go with UTH's you almost always want to go a size higher then your tank when placing it on the side. I would buy a 30-40 for a normal 10 gallon tank and place it on the back.