Turns out that Gmail won’t remember what UI you want to use. So if I switch to the old one, I have to remember that “?ui=1” query at the end of the URL every time, or I get the new version. If I think about it, the new UI isn’t that bad, and I would only really use the old one to get back my Gmail Signature Float script, which I only used for a link in my signature (Gmail doesn’t allow HTML for some reason). I can live without that; it only generated five hits in the last month. And it’s a small price to pay for the increased speed.
I’ll close with a few side notes about the new UI. Many people have already covered the major feature additions and improvements (speed, contact manager, contact popups, etc.), so I won’t go into them now. What interests me is the little things. For instance, running Gmail with the Firebug extension enabled in Firefox brings up a warning (not available in the old version) that “Firebug is known to make Gmail slow.” Also new is automatically updating “X minutes ago” text in the message headers. Whereas in the old version messages loaded and were stuck with “5 minutes ago” or whatever until you refreshed the view, the new version “ticks” every 60 seconds and updates all the time counters, so you never forget how long it’s really been.
Also changed: When something’s loading, there’s no maroon “Loading…” box in the upper right; it’s been replaced by a centered, fixed-position inverted tab in the top-center of the screen. Which is pale yellow. That brings me to the next point: The messages are now pale yellow instead of that wonderful orange (which I stole nearly exactly for one of my websites’ notifications). Of course, this brings along some inconsistency, since Google Reader still uses the orange color. I’ll be suggesting to the Gmail team they change it back; I liked the orange better.
Aside from a few minor gripes about unnecessary changes, I like the new interface. Now if they’d only add HTML signatures and the option to “float” them/remove the dashes, I can forget about the Signature Float userscript altogether.