I'm still debating with myself if I really need a Garmin/Bolt gadget or whether for the few outside rides I do I just stick with my Android phone and Strava (may pay for premium for a few months up to the DD). I have some vouchers for Amazon so likely to get myself a cadence sensor which I can link up to Strava (already have an HRM which links up).
Re the Pro, I'm going to hang on to this for those occasions when I want to race on an even basis on BSIM. I'm 99% on Zwift at the moment as pushing for the Tron bike and training for the DD, but when back in race mode I'll go back to BSIM until my subscription runs out (Feb?) then make a call where I spend y money each month. It's nice having 2 trainers, gives me options.
You should be able to pick up a 2nd hand Pro off
ebay for about £100 or there-abouts, so worth a punt.