Yes, didn't do anything unusual. Just used the provided Make_E2B_USB_Drive.cmd and the installed RMPrepUSB/RMPartUSB to format and create the E2B drive.
I tried several different USB drives, but the result is the same.

Without even adding any payload files, just a freshly created E2B drive, the loading of E2B menu is very slow on many older computers.

Speed results for loading E2B main menu following POST:
Laptop Lenovo R60, Core Solo, 1GB, Intel 945GM chipset - 10 seconds
Desktop Core 2 Duo, 2GB, Intel 945GC chipset - 85 seconds
Note these two above chipsets and USB controller are very similar, and the desktop is superior in all aspects, CPU, RAM, HDD, yet it is very slow to load main menu compared to the R60.
Other PCs I tried were even slower:
Desktop Athlon 64X2, 2GB, NVidia nForce 550 - 90 seconds
Desktop Pentium 4, 512MB, Intel 845G - 130 seconds

Does E2B really have that big of an overhead, or maybe something is wrong? How much data is being read during the main menu loading and what how many I/O operations? I can't believe it would be maxing out the entire 480Mbps and USB controller the whole time.