I'm not familiar with those particular extensions, but if this is your general reaction based on how heavyweight you think an extension is, you may be in for a

I'm not familiar with those particular extensions, but if this is your general reaction based on how heavyweight you think an extension is, you may be in for a surprise. An extension (like a password manager) loading something like jQuery for every iframe easily slows down a site like Gmail by a few seconds. Instead of guessing, I recommend using the Performance tab of the browser console (click the "Start Profiling and Reload Page" button) along with the call tree (group by subdomain) to see where most of the time is being spent. Also, Guest & Incognito seem to be intrinsically faster for some reason even compared to an entirely fresh profile, so you may want to compare against an empty profile instead.