I replaced a 5-year old 2 hp Stealth with a 1.5 hp ePump about a month ago, so I can report on my experience. My pool is about 24k gal, has a raised spa with 5 jets, solar panels on a 2-story roof, and a Ray-Vac cleaner driven by a 3/4 hp booster pump. My top tier electric rate is $.38/kwh, so I'm guessing 2 years or less for payback. The old 2 hp pump was pulling 9.7A/2230 watts running the filter, and 8.9A/2140 watts running the solar.
I chose the ePump over the Pentair for the following reasons: 1) The location of the pump inlet and outlet ports is only 1/8" different from my old pump, so I planned to swap out the pump without needing any plumbing changes. 2) I have the Jandy Aqualink Onetouch control system. That needed to be upgraded to the new revision P firmware (cost $650), but the ease of use of an all Jandy control system seemed better than installing the Pentair IntelliComm II interface and having potential communication problems. 3) I was doing this as a DIY to keep costs down, and the Jandy parts were cheaper than the Pentair.
Installation of the Aqualink upgrade and the new pump took me half a day, but was simple and straight forward except for one major glitch. My old 2 hp Stealth (model JHP 2.0) uses a fine thread on the pipe connection union while the new ePump uses a coarse thread, so I needed to do some plumbing work after all. My local Home Depot and Lowes do not carry PVC larger than 1.5", but the ACE hardware and a landscape supply store had a good selection of larger diameter PVC.
One great feature of the Aqualink upgrade is that it reports both the pump speed and power use on the indoor Onetouch control unit. The Aqualink allows up to 8 different speeds to be set in 5 rpm increments. I'm currently using 5 speeds, as follows: 1) basic filter pump, 1250 rpm, 115 watts, 2) spa, 3025 rpm, 1060 watts, 3) spillover, 2100 rpm, 350 watts, 4) cleaner, 1700 rpm, 235 watts, and 5) solar, 2630 rpm, 700 watts. I'm still fine tuning the speeds to find out how low I can go without creating any problems. I did notice the pump had a wah-wah-wah sound when I went below 1100 rpm, but it smoothed out to a purr when I raised the speed a little.
I haven't gotten a new electric bill since installing the pump, so I can't comment on energy savings yet. Also, I have been using the A/C a lot since installing the new pump, so I would be happy if the next bill is about the same as the last one. Other than the unexpected thread problem, I have no complaints with the installation and operation of the ePump. Let me know if you have any questions.