Difficult to say as I have only been a supporter for a week and have only done the one time contribution at this point to decide if it is worth subscribing too on a monthly basis. However in the terms of syncing, if like me you like things done quickly and don’t like to wait then Garmin syncing is super quick by comparison.
I think, having been on City Strides for some time but only just starting to experience the syncing issues as it becomes more popular (most likely due to Covid-19 restrictions) it was very frustrating to not see my life map updating as it has always done on the same day and with having to run more local than I would usually do the temptation to go and collect streets is the one thing that is keeping me going out the door every day. Being a supporter helps keep that motivation going when I see my completion percentages increase meaning I can wind my running buddies up as they fall behind so for now I am happy to part with a few quid to enhance the experience, I mean to be fair it isn’t much you need to part with each month for that luxury. The only thing that vexes me now is that my profile picture still won’t sync back and maybe will not do as I now have Strava sync paused so I’ll just have to wait for the option to upload one direct to my City Strides account rather than use the Strava one is developed but I can live with that for now.
All in all I think I will most likely continue to support, I like having the weather data on the run, the idea of the Re-Run option is good but could use some work, looks similar to Relive but there are a pair of running shoes moving along the route
If I am honest I think the answer to your question will entirely depend on what you want to use the site for, why not do a one time donation for a month and try it and see, you might decide it isn’t worth the outlay but at least you will have tried and given something back to James for all his hard work.