The command box is significantly slower in 7.8 than in previous versions. Whilst I appreciate the extra functionality, I don't want that to be at the cost of speed.
I use the command box most often to open resources. Previously, by the time I'd finished typing part of the resource name/author, the suggestion would be there. Now it's about 3-5s after I've finished, and I'm running a fast system with lots of RAM. I dread to think what it would be like on a slower system. Admittedly I have a large library, and that seems to be the problem. Everything I type has to be looked up in every resource to see if it's a reference.