I've had it a couple of weeks now so I'll give you my impressions. Firstly, the unit. I went for an expensive one as I love gadgets (I'm in IT) and plan on keeping my car until it is uneconomical to repair (first car I've ever loved owning!). I got the IQ90MTVL model (£429.99) but any model with at least 2 GB RAM will be fine. 4GB will be better. I also got the tire pressure monitoring (£63.99) , the ODB dongle (£10.99) and the DAB radio dongle (£49.99). I wouldn't buy the TPMS or the DAB from Xtrons again as they are over priced. Any USB TPMS or DAB dongle will work with this unit. I wish I'd known this before purchase!
Fitting. This was very straight forward as the Xtrons unit is made for the Skoda so fits neatly in to the hole the old system left. Access to remove the old system is extremely easy as you just need to use a trim tool to pull off the rectangle of black plastic which surrounds the unit and then there are 4 torx screws (T15) to remove. One thing to be aware of is if you disconnect the passenger airbag sensor which is connected to the black plastic rectangle, you will trigger a warning on the ECU and you'll need to clear it with an ODB reader. I left it connected and just rotated the plastic out of the way when I fitted the new unit (be careful not to scratch the new unit on it!). I also left the battery connected throughout. The wiring harness was simple as the new unit came with a quad lock connector that snaps directly in to the car loom. This provides power and connects the car speakers to the head unit. It does not connect AM/FM, DAB,MIC or GPS. The new unit came with its own aerials for DAB and GPS. Put the DAB one in the bin, it's useless. The GPS unit works but you want it to see the sky wherever you decide to place it so it does end up cluttering the dashboard. I bought a Fakra to SMA connector from Amazon to connect the car's built in GPS aerial to the head unit for £7.99. I bough a dual fakra to DIN cable to connect the car aerials for AM and FM, again, £7.99. I also bought a magnetic stick on DAB aerial which works well but does result in some ugly wiring. My car doesn't have a built in DAB aerial so this will have to do as no way am I messing with the headlining to put a proper aerial in. DAB aerial was £13.99.
The new unit. Nice, clean looking, large screen. I installed the Agama car launcher (£2.49 I think) after playing with a couple of other options and I find that Agama suits my needs very well. The unit itself seems well made, solid components and many many connection options. It has a DSP audio chip built in and sounds much better than the old RNS510 did. I love having the entire Android ecosystem available to customize the capabilities of the car. I am using Torque combined with the dongle I bought for real time engine information, the TPMS alarms audibly if it detects an issue. I have Igo, Sygic, Waze, TomTom, Memory map and Google maps for navigation which covers me for online and offline navigating, all with decent real time traffic monitoring. Poweramp for music, plex for parked up entertainment. The unit is snappy and fast. I added a 128GB SD card to its "GPS" slot but this is just treated as extra storage labelled GPS. I put my 90GB of music on it and it plays fine. The new unit is better than the RNS510 in every measurable way. The startup time is sub 30 seconds from cold, noticeably faster then the RNS510. Sub two seconds from "warm". The screen is clearer and brighter, the sound, especially the bass, is much improved too. Steering wheel integration has been fully retained and additionally is now programmable if you want to add more controls. You also retain things like the climate control settings appearing on the head unit when you make changes as well as reversing tones and display for reversing sensors (I don't have a camera but am thinking about adding one). The unit also allows you to add Skoda branding to it and match it's colours to your car's interior or any other colour you like. You can make it look very factory fitted as it has no branding on the front.
The bad news. Maxidot integration is affected. You no longer have music titles being reported and the sat nav no longer integrates. So far I have been unsuccessful in integrating the car's Phone hands free functions with the maxidot. The maxidot will still control the phone and allow you to make calls etc but it doesn't route the audio through the head unit, just the phone. This may be fixable as I learn more but I hardly ever use the phone in the car so it's low priority for me. This may be a deal breaker for some but I normally have my maxidot on consumption anyway so this doesn't really bother me.
The other big downside that I can see is that this unit really benefits from being online. You can download apps and maps and music and keep it all local but this unit shines most when it's able to get live traffic updates, stream spotify and other online activities. This means you'll want to either be getting your phone to enable its wifi hotspot each time the bluetooth connects to the head unit automatically (it's a pain to remember to turn it on and off each time you get in and out of the car) or you'll want a 4G version/dongle and a SIM to get the most out of it.
Overall, I wish I'd made the change sooner. The new unit makes the car feel like a brand new modern day luxury vehicle. It can provide a wifi hotspot for passengers, good bluetooth built in, can handle up to four storage devices (3 x USB and 1 x SD) up 10 128GB each and is blisteringly quick compared to the RNS510. Multiple choices of navigation/music/movie/game software that simply isn't available to the RNS. Easy to update as well as maintain and based on an operating many people are already familiar with from their phone. I'd never replace the RNS510 with another RNS510, it'll be one of these units from now on.
If you have any other questions, I'm happy to answer while it's all still fresh in my memory.