As much as I love my 955, and all the forerunners I have had before it (plus a 735 XT). I just can't bring myself to upgrade to a 975 if one fundamental issue is not solved... processing of third party activities for training load.
I use TrainingPeaks virtual for my indoor training, but only Zwift and TrainerRoad are supported for training load analysis. I use a Hammerhead Karoo for outdoor rides - also not possible to have them added to Connect and processed for training load.
This pretty much renders a lot of the great Garmin functionality redundant, and there is no way this encourages me to go deeper in to the Garmin ecosystem, in fact it's quite the opposite.
I also don't buy any argument that Garmin cannot trust the quality of 3rd party fit files. I use complex workarounds to take the files from Hammerhead and TPV, and 'fake' the fit file device so that Garmin thinks it came from a edge unit, and it works perfectly EVERY TIME.
A closed approach like this only pushes consumers away. Please Garmin, open up.