Second Life is serving up HTTP textures now (in most or all sims), and when they work well they are awesome. They’re not entirely without issues however.
If you are using an older viewer or a viewer based on a pre-Viewer 2.0 source tree you’ll need to enable HTTP textures manually. Go to Advanced > Debug Settings and set imagePipelineUseHTTP to TRUE to turn HTTP texture support on.
HTTP textures load quickly. Very quickly. There’s not all that much in the way of prioritisation, however. Smaller textures will almost inevitably finish transferring before large ones. It’s always been that way to some degree, but you’ll likely find it more noticeable.
HTTP textures can flood your connection. They’re coming in much faster than they were under the other protocol, which means more network packets per second. In times of heavy texture load your viewer can slam against the network bandwidth cap set in your preferences and SL protocol packets start to get lost. If your network bandwidth slider is set too high you’ll lose a lot of FPS. If it is set too low, you’ll slam against the cap.
The whole viewer can also freeze or stall entirely at intervals, followed by rubber-banding when it suddenly wakes up again if you were in motion at the time of the freeze. This might well be related to the network flooding.
All that said, HTTP textures make a heck of a difference to scene rezzing times.
You’ll want to watch your bandwidth usage with server 1.40. A very few sims I checked out last night absolutely flooded my network connection (a little in excess of one megabyte/sec) – but the texture console didn’t show any active transfers. Quite what’s causing that, I’m not sure about. Some other part of the protocol going a bit off-the-rails, I presume.