IMO go with the t%'s but what do i know? No the T5,s are not consider vho. But they will outperform the vho's. No doubt!
Pulse start metal halide lamps have been developed that generate the same light output while drawing less current. They also have the advantage of shorter start and restrike times. Because they were developed primarily for the retail marketplace, they have improved color rendering, and maintain a more constant light output over time (called lumen maintenance).
T5 fluorescent lamps are a reasonably new technology, developed in 1995, and T5HO lamps are suitable for gym lighting. The designation means:
T = tubular shape
5 = 5/8" diameter
HO = high output, 54 watts for a four-foot lamp
These lamps have excellent color rendition and lumen maintenance, and the highest lamp efficacy, measured in lumens per watt, of all the fixtures we considered. Light quality is further improved because of its diffuse nature, which reduces shadowing. Fluorescent lamps have the additional advantage of a near-instant start, simplifying the use of occupancy sensors or other usage-based controls to reduce burn time.
cut/copy and pasted from a coolege site.