Its logical that if the data is saved on a faster storage like HDD or even SSD the loading times could be shorter menus and stuff might be snappier. What framerate is concerned it should be similar or the same as most games on PS3 atleast take advantage of the hdd if it speeds up framerates to access the data from a faster storage instead of the disc.
I do think digital could ultimatively perform slightly better here and there because of the bandwith difference doesnt mean it absolutely has to be better always, depends on the game and the installation.
Someone would have to test each version of a game specifically and to make the call on whats better. But generally digital wont ever perform worse it will atleast perform the same.
If you dont mind skipping the disc using bandwith for the download and using space on the HDD digital should be the better choice.