I have done business with Hydroempire on and off the past several years, and have never had anything but a positive experience.
Their prices are the most competitive I've found, they have a toll-free number, free shipping (with minimum order) and if they don't know something they'll do their best to find out for you.
Service was ok, and the prices and shipping were reasonable, however, and this was a really big problem, they sent my stuff by UPS. That in it self wouldn't be a problem, but they sent about $30 worth of seedling supplies as "signature required". Since I work, as most people do, and as UPS only delivers monday through Friday, I ended up having to drive about 80 miles to get my stuff. To make it worse, I emailed them twice to see if they could change the directions to UPS or at least get an explanation as to why they sent it like that, and I got no response from either email.
That's the last time I will order anything from them.