@itbeyond As always your mileage will vary depending on experience and goals.
Disclaimer: I only have a couple of MYS-sensors and a small OpenHAB installation for sensing and remote light control. OpenHAB is a complex system so it takes time to master. Fortunately it also has great support and I really like it for its flexiblity, power and structure.
MQTT or ethernet bridge? I've tried both but never got MQTT to work. Based on the questions in the MYS forums I believe it is easier to use the ethernet connection. I find it easier to troubleshoot. You can start with the ethernet bridge to ensure everything works. Then you can easily switch to the MQTT setup if there are advantages for you. But unless you have other applications that also listen to the MYS messages, I can't really see any obvious reasons to use MQTT. (Of course, it may give you a warm, fuzzy feeling of having an all-MQTT sensor network.)
Definitely go for config files. Autodiscovery is neat but there are many things you can't do in PaperUI or that are very difficult to do there. In config files you can also add comments to explain to your future self why you did something.
You can try autodiscovery and PaperUI first if you like and then move to config files. Then you may want to check out the OpenHAB forums on how to manually clear the cache. Sometimes the OH cache is a bit too clever for itself.
As I understand it, OTA is not supported by any MQTT controller. It is also not supported by OpenHAB. If you use the ethernet bridge you can keep your current ways of working - sensing and control in OpenHAB and update OTA via MYSController. If I'm not mistaken you only have to configure the MYS gw to accept at least two connections.
You seem to know your way around OH already, but I will add a few general comments for beginners, based on my own experience with OpenHAB (as a non-developer):
- First step is to set up backup and restore. Then test that it really works the way you intended.
- Use the production release of OpenHAB unless you really need the bleeding edge. It can be very time consuming to revert from a beta/snapshot release to the production release.
- Spend some time setting up OpenHAB and software around it so you can easily edit the config files. I use Openhabian which automatically shares all interesting files using Samba. It is then trivial to connect from my desktop and edit with my favourite editor. (MS Code has great support for OpenHAB config files.)
- Spend some time on how to properly backup and restore OpenHAB so you can experiment freely and still easily revert if it crashes.
- The OH forum is your friend. It is even more true than for MYS.
E.g. check out the advice on how to name (and not name) your config files, things and items.
and the OH patterns that provides beatiful solutions for many "impossible" problems.
- Did I mention backup and restore? At least archive your config directory regularely.