I decided to go with T5 HO a while back. My main problem with the LEDs was that while they save electricity and have a longer life, I read some posts about problems with the units burning out.
At the time, I was considering a Solaris system (now out of business) that would have cost around $3,500. I would have been happy to pay that if I hadn't read so many complaints about sections burning out. If I'm spending that kind of money, I really want a reliable product.
I'm not sure how the newer systems will pan out. I saw some at an exhibition a week ago, and they looked awesome. However, I still have doubts about the longevity of new products, and also about the warranties from some of the smaller companies.
I went with a Tek T5, and when a ballast blew, we got it replaced (at no charge) within a week.
My advice on lighting, if you're planning to spend a good amount of money, is to go with a reputable brand with a warranty and buy from a vendor that will give you real customer service. Buying the cheap brand usually results in buying another fixture 12 months later.