I own both the RKL and the Apex Lite, they are both great investments. But I personally give the edge to the Neptune. It looks more expensive at first but by the time you make a RKE net ready the prices are pretty comparable. I purchased the RKL Plus for $279 (awesome deal for what you get) two weeks ago and the Apex Lite for $369 plus $45 for the PH probe. It sucks having three tanks in two different locations. Also I heard Neptune is coming out with another Apex Model that will start at around $150. If you are a true gadget person like me spend the $$ for the Neptune.