well from experience id say the t-rex uvb bulb/heat lamp worked best for my frilled dragon. hes in the largest exo-terra tank with a screen top. however like i said with that is that they dont last to long. and can short out very easily and cost like 50 bucks to replace every time.

after that died i tried swtiching to a coil uvb bulb for temp usage. lets just say my guy wasnt recieving his normal dosage of uvb. and i quickly scrapped that one.

last i went with the reptisun 10.0 and he is flourishing fine. no problems or defects and he hasnt had any problems so far. and my guys been through a lot. hes been thru a prolapse, and topic skin infection. but hes 100% now