Essentially, it is better to have a fast snappy app with poor design over a high-latency app with great UI design.
Users subconsciously attribute delays caused by bad UI design to themselves, but if you have latency, you are screwed b/c that's delay is subconsciously attributed to your software.
In the end, users can learn to navigate a bad design quickly as long as the page loads are fast, thus making latency the most important factor in usability.
Essentially, it is better to have a fast snappy app with poor design over a high-latency app with great UI design.
Users subconsciously attribute delays caused by bad UI design to themselves, but if you have latency, you are screwed b/c that's delay is subconsciously attributed to your software.
In the end, users can learn to navigate a bad design quickly as long as the page loads are fast, thus making latency the most important factor in usability.