The PE653RC looks like a pretty nice device. I just glanced at the installation manual a bit to see what it had to offer. The biggest issue I can see for the installation would be figuring out how to enclose the wiring. I have a Pentair system (way more expensive) that includes a "load center" which is really a weatherpoof breaker panel plus a place to house the electronics and relays. It looks like you'll need to build that yourself with the Intermatic system.
The pump the reviewer is referring to is a pentair intelliflow. It's variable speed, very quiet, really efficient, and quite expensive. It has a local LCD control panel that gets locked out when being controlled by it's rs485 interface. When the Pentair control system is put into "service mode", the panel releases the pump to allow for local control... sounds like the PE653RC could be missing this feature. If you search the forums here for "pentair", you'll find a couple of threads about controlling the pump without buying a pentair interface. The price of PE653RC is pretty good for just that alone.
I really like my IntelliTouch system but have always thought it to be overpriced. Had the PE653RC been available a couple of years ago I am sure I'd have given it a much closer look.