While SU16 beta is very stable generally, I have had a few WASM crashes in the A20N v2 while setting up a flight on the ground at various 1st and 3rd party airports
I’ve also twice had it where I was unable to load fuel and payload into the v2 through the EFB. Payload and fuel window wouldn’t work either. Ok after restarting the flight
I just flew from Heathrow to Beirut on an LVFR A321neo. Night flight. Overall smooth flight. I had some stuttering on the way out of the airport and the night lighting was loading in blocks. But overall positive experience so far. I think there is more room for improvement in the LOD, PG and loading issues. When moving to the cockpit, there is quite a bit of stuttering. I still dream of getting back to using the 787 smoothly but this is what it is for now.
Yeah 747 and 787 were broken by the avionics update. I find they work fine during the day as long as you only have a single figure number of waypoints in your flight plan. Any more than that and the stuttering starts. Night flying also a bit problematic in them
Flying all over Europe since yesterday, I had only 1 freeze and had to restart the game, otherwise it looks ok. SU 15 was quite stable for me up until ~2 weeks ago, where it started giving me CTDs a few times per day, so I disregard the last 2 weeks and rate the SU 16 beta stability as ‘about the same as the current public build’. That is mainly because something obviously went terribly wrong within the last 2 weeks - not on my side as I have not changed or installed anything - and I feel like comparing the SU16 beta to the last 2 weeks of the SU15 would not reflect the real changes.
Next test will be flying around northern Italy, where I had like 80% chance of a ctd in the SU15 and before. If I do not get any ctds there, I will change my rating here.
Edit:
Did 2 flights over Italy, in an area that was almost a guaranteed CTD in the SU15 and earlier, no CTDs yet in the SU 16 beta. Will do more flights later, but it looks promising.
Edit #2:
After even more flights to various places that almost always gave me CTDs, I have not got a CTD yet. I have already changed my vote in the survey, it looks like this build is more stable than the current public build.
I kept the same settings as I used in the public build, so PG and bing maps on, live weather on, live traffic off, multiplayer off, ground vehicle density etc. set to 0.
Quite a few flights now on this beta and no CTDs even with PG on
Mind you I don’t have any third party airports installed - just have a selection of seafront simulation ship traffic - global, southeast, southwest, Channel Islands - installed as I like to see ships when I cross the water. I know from bitter experience that third party airport add ons can cause stability issues on Xbox so I avoid them.
This beta build with WASM working has been beautifully smooth and stable for me so far…. After each flight I exit and restart flight sim….
But I know that might not be the case for everyone..we all have different preferred configs and settings.
What settings do you use? PG off/on? LIve traffic? weather? Ground vehicles density? Rolling cache?
Do you own any PMDG aircraft (737? 777?) and have you used them in the SU16 beta? How do you set them up? Do you start with cold and dark and do everything manually? Do you fill the flight plan manually or through Navigraph?
I would like to copy your settings. My console is fresh after factory reset, freshly installed MSFS and the performance for me is noticeably worse than in the SU15. Stability though is better as far as I can tell.
XBOX X PG off, Live weather on. 6hr+ flight 777F OTHH-LFPG. Lod improved. Performance same as su15 (40-50fps). Lots of new bing maps artefacts on the way (still nice to have new maps ). Small stutters over Alps. 5 hrs of decent stability and perf. The worst came on approach to ILS rwy27R LFPG (Asobo handmade airport ) - freeze, then avionics black screens, then avionic is back (with broken wxr on mfd), then on final again blackout of avionics (no recovery).
After this flight I uninstalled all international custom airports (only ag airports), I lost fate xbox can lift such planes as pmdg 777 and 737and big airpotrs at once…
Not a big deal for me, airport is like 5% of my flighttime but still a shame.
Please provide additional information in the comment section below 
Reminder:
). Small stutters over Alps. 5 hrs of decent stability and perf. The worst came on approach to ILS rwy27R LFPG (Asobo handmade airport ) - freeze, then avionics black screens, then avionic is back (with broken wxr on mfd), then on final again blackout of avionics (no recovery).