I have two tanks 3 PVC enclosures (well two pvc and one poly carbonate) and a 5 hole rack. I prefer my custom poly carbonate first and then the PVC, Tanks, and then the rack. The rack is the hardest for me to heat and with my rough knees the hardest to clean (i am a big guy 6'4" and 230 fitting into a 6 inch by 18 inch opening and reaching back almost two feet is not easy) The only advantage the rack has is space saving.