haha, you win. I agree, things are expensive in this hobby of ours, but I've found that if you are willing to spend the money on good things up front, then life is much easier in the end.
And no, I don't consider maxi mods a complete product, because you can't just buy the powerhead off the shelf completely modded at a reasonable price. You need to read about the whole process, then you need to acquire the materials (a little easier since they've actually got a site which sells all the materials), unless you are willing to pay 60 bucks for a premium kit from oceanflo and then that doesn't include a magnetic mount, which is completely manueverable. So in the end, is it really worth the time when some people make a good enough living, that the little amount they save on DIYing it would actually not save, but lose them a substantial amount of money and time. Not everybody wants to spend the time constructing a maxi mod and wondering whether it will work or how long it will work. It's simply not worth the trouble for some people.
Honestly, we could argue about this all day... you won't buy a Tunze and I will. Haha
The 660 gph model is for people who don't have a big tank and it's probably making a lot of people with nano tanks really happy. If you need more power, then go for the 6045 and if you want controllable, then go for the 6055.
There may be very good things coming down the pipeline, but right now, the selection is limited and the Tunze nanostreams are definitely filling a niche where many people have been looking for something compact, versatile and dependable.
Peace,
John