I had the opportunity to record a bunch of kids getting ready for music competition, and found the 60d easy to use laying flat on the battery door. The audio quality was respectable, IMO.
I didn't compare the 60d to the 2d, but I did compare it with the M10 and 680 on piano in a more controlled test. I had the pianist listen to all three recordings later and the pianist's order of preference went: 1) 680; 2)m10 3) 60d. The 680 and the 60d both used line audio cm3s. The m10 used AT853s>BB>M10. I was sort of surprised how well the M10 setup fared in my test to the point that I returned the 60d since the M10 setup worked so well and I already have the M10. If I need more channels, I can use my 680.
With the 60d also offering 2 xlr inputs with phantom power, the 60d looks to me to be something that would appeal to 2d users who want to record a feed off the soundboard and also record with their own mics without having to add external setups for phantom powered mics.
Size wise, if the 2d is about the size of a thick pack of playing cards, the 60d is about the size of a box of bill paying envelopes. I like the layout of the controls on the 60d, and much prefer the rotary gain knobs to the side mounted gain control on the 2d.
2d users will immediately be able to grasp the 60d controls and menu with the 60d overall layout being much improved over the 2d, IMO. The 60d uses a rotary menu selection knob instead of the disc wheel used on the 2d. IMO, the 60d's menu knob is an improvement.
Obviously, the 60d is aimed at providing audio recording to DSLR users and appears well suited to run and gun audio recording on a budget, IMO. The boxy shape of the 60d could lend itself to some DIY case to protect it in travel and maybe hold an external battery, too. The screw in camera mounting plate on top obviously gives an extra place for mounting options besides the 1/4 case thread on the bottom.