We've been using an Envirocycle for about 13 years. Same principle as the Taylex brand, with a different internal design. I was originally going to install a Taylex, but got talked out of it by the plumber. He said the pumps we're a bit undersized (but that was 13 years ago, so I'd guess they're better now?). I've had to replace the air pump twice in its life and the sullage pump once in the envirocycle, so maybe the pump issue is just normal maintenance for any of the brands?
Check with your council on the local regs for the water discharge, as they will vary between councils. There will most likely be rules about how close it can be to any other water source, boundaries, walkways/paths etc.
Some councils will let you do a course to self-service your HSTP, we just went with a local service provider who turns up when it is due (quarterly) and does whatever he does and leaves a report in the mailbox.
They are a Bio system that rely on the bacteria to do it's job on your job, so you need to be a bit selective about what goes into your waste water from the house. No bleach or chlorine based cleaners or you will kill the bacteria in the system, and if your taking antibiotics for medication, throw a handful of blood & bone (or some sugar) down the loo help. And no excessive amount of milk down the drain.
