There have been many awesome advances in lighting technology since
VHO was introduced. While T-5 has smaller tubes, they also have smaller wattages and many would argue that the lighting is better.
VHO in 4ft lengths are 110 watt and
IMO has better light output. Again, that poses a debate on any forum... This is JMO. I would do more research as to the spectrums and intensity before making a decision....
Also, you may want to look into the possibility of
MH lighting and just supplement with
VHO, T-5 or
PC.