I don't have an issue with the announcements being in Welsh and English, but I do have a problem with the sheer amount of announcements and unnecessary length.
As mentioned earlier, there is no need to announce "Thank you for travelling with TFW" at every stop and so on.
If it was as the same format as the legacy fleet but multi language it would be OK I think.
Currently you have (on 150/3/8), English only) :
-"Welcome aboard, we will be calling at X,Y,Z" at the start of the route/following major stations.
-"We will shortly be arriving at X" on approach to a station
-"This is X. This train is for Y" once doors open at a station
-"This train is for X, the next stop is Y" on departure from a station.
-"We will shortly be arriving at X, our final station" on approach to the terminus.
I feel the short but sweet setup Currently used on the sprinters would be acceptable in both English and Welsh, whereas the 197 setup is just too much.
Avanti have the right balance when their services announce Welsh and English on Holyhead routes I find.
EDIT- Forgot to add, this has been raised by staff internally and they are looking for feedback on ways to improve the announcements. Obviously it has to include a Welsh version, but it is being looked into.