I personally do not recommend a 2 in 1 either. I know alot of people use them without issue.
But Krunch came to me with MBD, and had been raised with the powersun. I attribute his health issues at least in part due to the powersun. It was too hot to sit under, therefore he didnt get the neccesary heat requirements to digest food properly or the necessary uv for proper calcium utilization.
He is a different color thought from the usual Nosey, completely lime green, old school, no blue to be seen on him and that I believe has an affect on how much heat he can take.
again, just my personal experience,
anne