I did the discover europe last July with topdeck and going again with them in June to do Britain/Ireland tour. I have had great experiences with topdeck and I cant wait to go again.
When i decided to do a trip overseas, I went to my travel agent and got a topdeck brochure and went through ALL the europe trips and taking into account different options (how long I wanted to go for, cost of tour, places I wanted to go, when I wanted or could go with my work ect) and made my decision that way, just working my way through and finally found one that suited me. I was travelling alone so I wanted a tour where I could meet lots of people and see as much as I could.
I brought europe travel adapters (u need at least two I think to charge camera, phone, ipod ect) which was called Journey by KORJO, they have listed on the back which countries are compatible to use the adapters in, didnt have any problems with them on my tour.
As far as I have experienced and read on other posts, there are no usb ports on the buses.
Good luck, hope that helps