At least for firefox, there's an old reddit redirect extension that automatically rewrites any reddit urls to old.reddit.
I warmly recommend that one. Except that since the latest firefox mobile release it hasn't yet been ported. But given that it does exist on the desktop version, I guess it's only a matter of time until it reappears for mobile firefox as well.
I have a tiny script added to TamperMonkey that redirects every reddit URL old.reddit.com equivalent. Funnily, the redirect ends up loading more comments faster than the redesigned "new" site with 2 comments
