We recently switched from GIFTS Alta to GIFTS Online in the last 3 months. It is painfully noticeable to me that it is slower. My clicks used to be instantaneous, now it takes a second. Which isn't bad at one time, but when it's the culmination of the whole day of working in GIFTS Online - it is frustrating.
Also I get icons that show me GIFTS Online is loading. It usually only takes 5 seconds, but again, cumulatively -- this makes my work feel far more tedious than it used to.
My computer was just recently reimaged, so it isn't an issue of old software or bloated PC system.