I like the Biocubes and I also like the Solana. I have a couple 14gal Biocubes and also a 34gal Solana. I also had a 8gal Biocube at one point.
Biocube Pros:
Closed hood setup = very little evaporation. I have been able to go on vacation for around 10 days without a problem and without having an ATO.
2nd chamber works as a chaeto chamber.
Biocubes seem fairly well made. Tank isn't rimless, but the AIO cube setup looks nice.
Bulbs are available at the local Petco/Petsmart.
Biocube Cons:
No included skimmer. Hood limits skimmer choices a bit.
With Halide lighting, the closed hood setup might retain a lot of heat. But, I have only personally used the built-in PC/T5? lighting and an Ecoxotic LED module.
Glass is curved. The curve on the glass creates distortion.
Kind of a pain to clean the front corners of the glass, because they are rounded.
Soft glass that scratches easily.
The ballasts fail with the PC/T5 lights. I've had 4 ballasts fail (out of 6, 2 ballast per tank) with the biocubes. This is the reason I no longer have the 8gal Biocube. Both ballasts failed so I tossed the tank. This is also the reason I have an LED module in one of my 14s.
The stand feels kind of cheap, but its also fairly inexpensive and has had no problems after several years.
Solana Pros:
With the glass top, there is very little evaporation. I have an LED over the Solana. Halides and the glass top might cause the tank to overheat, but I have no idea.
Glass is straight. No viewing glass distortion.
2nd chamber can be used for chaeto.
The wooden stand is high quality and looks like a piece of furniture.
Can put stuff in the chambers easier because there is no hood to get in the way.
Solana Cons:
The included skimmer is horrible. There may be cheaper and better rimless tanks because of this.
The walls and dividers of the chamber area are super thin and feel cheap, but they seem to be fine.
Rimless tank. Personally, I have concerns with hanging things on the tank.
Soft glass that scratches easily.
The wooden stand is expensive.
Not much point of the 2 top-off bottles for daily use. Easier just to pour water into the 3rd chamber. The bottles would probably work out okay for a week trip as a cheap ATO.
Overall, I think that they are both pretty nice.
