I switched when 4.7 dropped, after over a year on the service. It was an immediate improvement - not even 1 hour before Codex was giving me better results with less effort.

Unfortunately Sol does not compare to Fable at all.

Stick with xhigh rather than turbo for most tasks though, now that the Age of Abundant Resets seems to be well and truly over for good (and 5h limits are supposedly returning soon).