Son Agro/Radium Bulb Life

[Aquattro]

Also, if the bulb lasts only 9 months, the cost per month is very close to the much more expensive Ushio 10k bulb. For pennies a day difference, I like the look better.
Personally I don't like the color from the "proper" M135 ballast, so to me, I don't care if it lasts forever.
Basically, as with all lighting questions, it comes down to what you want to pay for the "right look". And that look is different for everyone.