2000 I was using Neptune with their X10. Worked well until my young GSD thought it was a chew toy... Later picked up a Reef Angel that has been running strong the past 7 years. Zero complaints. Recently upgraded so purchased a new Apex and again like what it offers. Here is my question because recommendations are somewhat biased from us who reply.
1. Do you want a closed system off the shelf or are you open to open source?
2. Do you have basic coding abilities,willing to learn, and some handy dandy DIY skills?
3. Or...do you just want something to plug and play with auto config wizards?
Reason why I ask is because if you are open to open source, DIY, and have some basic coding skills something like the Reef Angle or Pi will probably fit your needs. On the other hand if you want more polished over the counter stuff then you are looking at Neptune or GHL. Having both a Apex and a Reef Angel I can say the RA still does some things 100 times better than the Apex or even what I know about the GHL. On the other hand I will say the Apex and the GHL are more refined and polished product with a better build quality in the end.
Really up to you. If you do say go with a Reef Angle or other open source make sure to read their forums for a bit to see activity and current trends. I know the RA just came out recently with a new version, Star, and it has had a few issues. Roberto is amazing in support and managing issues.