I just bought the 24" Odyssea 250watt MH w/ 130watt actinic. I've had it for almost two weeks now, so far, so good. I retained the box it came in, as 30 day returns are accepted from this ebay seller, just in case anything happens. Before that I had Odyssea 36" CF fixture, It lasted almost 2 years before the ballast blew. They are far less expensive but have to be replaced more frequently, so there's the trade off. Personally, I'll go with cheap for now, with the understanding I'll have to buy a new cheap fixture in the future. I personally prefer that over keeping the same old (but expensive) fixture for 10 years, this way, you get to take advantage of new technology as it comes along.
Kinda like buying a vacuum cleaner. You only have to buy a 2000.00 dollar Rainbow Vacuum once, but it has to last 20 years to pay for itself. I'd rather have 12 new Sanyo vacuums and no be embarrased of the 20 year old vacuum I keep hid in the closet.
