I am pretty sure that Sylvania uses amalgam mercury which is why the tubes require warm-up time. The quality of the tubes is decent - if they are used commercially they generally perform well. I will agree that some of the Satco fluorescent products are good, although their incandescent bulbs are junk. I have had some
Satco 5 Watt CFLs running for years - one failed early, but the other five are still going.
However, I think GE currently makes the best fluorescent tubes - they seem to perform well and have good light output. I put 15
GE F28T8 XL SPX41 ECO tubes into use at work (some of them run 24/7) over two years ago and none have failed, nor do they look like they will be failing anytime soon. The fixtures are even instant start!