I've had my E-Neptuno flying for a couple of months now, but wanted to get some things worked out before posting.
A little background on myself in order to take my comments in context: I've been flying IMAC for about 6 years now, but just got re-started in pattern 2 years ago after discovering how well the planes fly, how cool e-power is, and how fun sequences can be without zillions of snaps. The Neptuno is my second 2m e-plane; I flew a Delro E-Motion last year in Masters and FAI. I'm competent, but no threat to win a decent sized contest. Still learning about pattern trimming and setup.

First, the model: For $2050 shipping it's hard to imagine a better fit and finish on a 2m model. Paint is immaculate, level of assembly is incredible, hardware included, and quality is top-notch. There were really no quality issues or flaws (other than a missing clevis) of significance. Derek's service is also top notch.

I first built the plane with a Himax. It was a couple oz over 5lb and felt it was underpowered compared to the Plettenberg I was used to, so a swap to a Plettenberg 30-09 and CF prop solved both issues.

I started with CG at 170mm from the wing root leading edge. The first few days of flying left me wondering if I had made a mistake. I was struggling with getting the rolls axial, it wouldn't snap without a ton of elevator and aileron throw, and didn't feel groovy through corners. I gradually moved the CG back and WOW: at 190mm it came ALIVE! I ended up at 192mm and didn't need the added battery tray Derek suggests.
It now rolls like it's on a string, snaps crisply and stops on a dime, and carves through the corners. So, maybe I'm giving up something with my preference for aft CGs, but that's what works for me on this plane.

Hammers are sweet and kick over at moderate throws so that I won't need to be flipping switches during a sequence.
Snaps like to be started with hard elevator before beginning rotation in order not to loose altitude, but finish crisply.
Point rolls require just a breath of rudder/elevator to maintain line.
The plane flies steadily in the wind, but does not "self correct" (yaw/pitch into the wind to automatically correct the line) as well as the EMotion does.
Incidences were set well at the factory and I think required mixing will be minimal.

I had a landing gear mount failure today during a good landing (on a moderately rough runway). The LG plate seperated from the forward former - looks like there wasn't much glue in the joint. So, think about reinforcing the mount.

So, I've started the trimming and "bonding" processes with the plane and give it a big thumbs up!

Dan