I do wish I waited for hydraulic. No way I can throw away the $$$ I spent on the etap wifli and then spend a lot more on hydraulic. But any excuse in the near future will give me reason to swap. Hydraulic really makes sense on the tandem too.
HY/RDs are a big step up from BB7s. I doubt you'll feel like you are missing anything from a full hydro setup. You will definitely gain a better looking front end on your bike, though. Hydro levers are simply ugly.