The weather hasn't cooperated very much since obtaining the unit but I have had a chance to hook it up to my 4096 TIC encoders on the Half Hitch II, do a 2 star alignment using SkySafari+ on both my iPhone and iPad, and hunt for some targets to test it out. I need to spend more time with it to confirm the accuracy at higher powers but so far, I'm pretty excited about this little gadget.
The Nexus is about the size of a Skycommander XP-4, weighs even less and fits pretty nicely on the fold out tray of the Half Hitch. The encoder cable plugs into the unit and after pairing wirelessly (pretty simple procedure) with the iPad, you start SkySafari and connect using the "Telescope" setting built into SkySafari. This differs from SkyFi, as I understand it, which can be made to work with a Push To scope in conjunction with an XP-4. The Nexus avoids the "middle man" so to speak, and passes encoder settings direct to the iPad, Mac, PC Android, etc. - although I am personally only interested in it as an iPhone/iPad solution. I guess it is fair to say the Nexus is more like a wireless version of the Dave Ek DIY box (although a Bluetooth mod has also been described).
For me, it is a real pleasure to use that big iPad screen to find objects and track my scope movements as I push the scope around on the Half Hitch. It offers a compact, fairly simple grab and go solution. The Nexus has a number of other features (e.g., serial to WiFi, simple camera shutter trigger, firmware update via USB stick) most of which I've yet to try.
The one issue so far, which Serge warned me about right away is that the Nexus drains a 9V alkaline battery pretty quickly when using encoders and WiFi. The Nexus has a connection for an external 9-25V DC battery. I had a Tekkeon Li-Poly battery lying around which I decided to hook-up and this is turning out to be a great solution (compact, high capacity, good cold weather performance).
The attached image is just to show the Nexus and give you an idea of the hook-up with the Half Hitch. The Tekkeon battery is larger than the Nexus and I've got it attached with Velcro to the underside of the HH fold out tray. The Nexus is communicating with the iPad and SkySafari with the cursor showing the scope "position" (not aligned to sky indoors obviously). Pushing the scope around moves the virtual sky around the fixed scope cursor or other way around depending on how you set it.
The iPad is mounted in a Delkin "Gecko" iPad1 accessory holder and attached to a Manfrotto "Variable Friction Magic Arm" held by a "Super Clamp" (attached to tripod leg). It is very easy to adjust the position of the iPad with this set-up. I will continue to put the Nexus and iPad through their paces in coming days and weeks and I'll update with any new thoughts as I go along but I'm pretty confident this is going to be a sweet set-up for anyone wanting to combine push-to with the great GUI (and extensive database) that the iPad and SkySafari plus (or Pro) can provide.