same thing happened to me.. did they let you keep the old mx duo set? they let me keep mine (the mouse works perfectly fine)
i like the keyboard A LOT better.. seems much sturdier and the newish button configuration i like a lot.. typing also feels much better.. more similar to a nice dell quietkey or whatever they're calling them nowadays.. overall much more attractive looking keyboard
i agree with you on the mouse.. it feels weird but i think it may just be changing from a slightly different feeling mouse.. before the mx duo i had a click plus mouse (not as good as this one, but same design) and i like it a lot... when switching to the mx duo i didn't like the mouse at first, and now i prefer it over the click plus.. i imagine i'll get used to it with time 🙂
edit: original message was posted about 10 minutes after it came in the mail. after installing pinpoint and messing with settings, i like the mx 700 set a lot.. the mouse wheel can click left and right, a nice feature.. also the keyboard has holes all the way through, so when you go to clean out the keyboard, you dont have to take it apart to actually get crap out. the only complaint i have so far is the with all the customizable buttons, you can't make the 'burn' button work with nero (at least i haven't figured out how).. i am quite satisfied with the free upgrade 🙂