The newer version takes more time to load but once it has done that, the mail handling part is faster. It must be said though that on the new gmail, the inbox width (the part showing the mail details) is small then a fraction after I open up the tab (I open gmail and a few other sites at a time and then come back wen gmail has loaded).
This snappy quality and the increase in initial load times are points of concern for me. Other than that, its quite good
/ 
