I know a few people that have gone down this route, and I am not aware of anyone that was pleased with the service, pricing or outcome. It's not a terrible option, but unless fox has already worked with an OEM on their tuning and shim stacks for that frame, you're just going to be getting a stab in the dark or just an off the shelf medium tune with either shim pre-load (digressive) or linear. While that is a pretty big impact in either direction... it's not going to net you much in terms of knowing that it's setup properly for your usage of the bike.I’m contemplating the next shock in my life. There are a couple of intriguing platforms, though no matter the route I take, I’m 210 with riding gear on and would likely benefit from a custom shim stack. Rather than buy a shock and send it to a custom tuner, it appears that you can get a “Fox Factory Tuned” shock directly from the manufacturer. This could greatly simplify the process, if their tuning process is any good. Seems like the new Float X has promise for custom tunes, for example. Do they actually custom design a shim stack for you, or is it more of fitting just one of the 3 pre-defined high-medium-low compression stacks before mailing it to you?
I do not know what frame you have, but i feel that the best option would be seeing of a rockshox superdeluxe can fit... and then finding one that is 2018-2019 aged and sending it into vorsprung for a tractive tune.