Great thing about the light tube, I can always swap it around to face the other way if I see one side is growing dis-proportionate.
In your shoes, I would probably make a point to do that on a daily basis (owing to the fact that I cannot think of a way to fabricate a revolving cool-tube that would do it constantly at around 1 RPM).
In regards to longevity, I don't use bulbs more than three grows, by then they have payed for themselves 100x over. I have found that any investment I make in my horticulture is repaid x4 in return, so what may seem pricey intially is only a drop in the bucket to what the rewards are. If it turns out the bulb is worth the extra price, I'll get another after this one expires.
I DO see your point here. But still, something deep inside of me has always balked at paying such a high premium when it is not deserved (say for a difficult creation or extreme creativity).
Instead of its expected usable lifetime vs. other bulbs I should rather have asked if this type of bulb's failure rate is higher than a 1kW HPS (or a 600-watt HPS and a 400-watt MH). For I too never operated a bulb more than two or three grows before relegating it to emergency spare status or giving it away.
I'm running a digital ballast (quantum 1kw) so energy loss should be at a minimum
I would not think the ballast type would have any real impact on that question. This bulb is intended to operate from a HPS ballast? If so, it must have the same hardware inside it (IMHO) as a 360-watt MH "conversion bulb" that is meant to operate on a HPS ballast. And they are only 360 watts because the hardware that allows them to operate with such a ballast consumes ~40 watts. But that is only my speculation and I would only expect about the same loss (which is relatively small).
The spectrum is better overall than the enhanced hps I was using, as far as comperable? I guess it would depend on which bulb you're refering to!?!
Either a 1000-watt HPS or a 600-watt HPS & a 400-watt MH.
I would think that - assuming that the bulb was regularly turned around so as to provide as even a coverage as possible during the course of the grow - you would have a harvest that is a little more compact, a little bit lighter, and a little bit more potent than if you had used a 1000-watt HPS. And pretty much the same (only a tiny bit less) than if you were using a 600-watt HPS & a 400-watt MH.
Again, that is only speculation on my part. I will be following your grow in order to learn what is actually the case.
And as always, good luck and thank you for experimenting!