So I set up for a EOS Utility test with all the same gear (my one mk3, Canon USB cable, laptop, etc.) and everything ran smoothly (!) The only difference that I can think of was that the card in the camera was a fast SD instead of the fast CF that was used in the session that gave me problems last Wednesday. I will continue the checking tomorrow, especially with different cables and cards. I have an extension cable that Amazon reviewers claim works perfectly to try out, too.
This same laptop and my 5Dmk2 (v2.9 and v2.10, I believe) never had the hiccups.
When LR4 can tether it may be cleaner but it won't have as many camera control options. Paul, I remember BreezeBrowser in its earlier days. I had *no* idea they built tethering capability! I will see what they have done with the mk3. But, again, the camera control in EOS Utility is cool.
I haven't made a LR4 watched folder import automatically, either. Tried, but no luck yet! Gotta make this work reliably!! I shoot with tilt and shift lenses and the live view focus checking is great. Easier than running the 8x loupe all over the ground glass under a stuffy cloth at the back standard...