Electronic or mechanical shifting?

[carbonazza]

After a very gratifying MTB build.
I got a kind of virus, and cannot think riding a road bike without building it.

My first doubt is about shifters.
Electronic or not?

Here's the first answer I got:

Personally I think Nintendo gears are the best thing since sliced toast! The price, less so and until someone starts paying me in something other than cake to ride bikes I can't justify Ultegra/dura-ace prices so Di2 105 needs to hurry on up.

Sram Red is iirc still the lightest groupset if that's your thing (I stopped being such a weight-weenie after about 30 seconds of playing with http://www.analyticcycling.com/ForcesLessWeight_Page.html)
Sram also have a wireless electronic groupo on the way but not till next year some time and I'm not expecting it to be cheap.

[carbonazza]

The price looks steep indeed.

I checked on bike24.com and the full Ultegra set is 1200€
With the groupset and brakes(vbrakes not disc).
http://www.bike24.com/1.php?content=8;navigation=1;menu=1000,4,26;product=24763

Peter is even selling a specific frame for di2!!
http://xmiplay.com/ProductDetails1684

Considering the set is probably the most expensive parts of the bike.
And the savings on suspension forks.
This looks it would end cheaper than my mountain bike.

I must stop this now, when it is still time

[Vipassana]

I've heard some very glowing reviews of the DI2 group from various users.  There are some very neat features like automatic trim adjustment on the front derailleur as you run through the rear gears.  Apparently the shifting is lightening quick and more precise than you can believe.

I wonder about the battery life on the DI2 system.  I did a century road ride back in May and ran into some poor old dude at a rest stop who's battery was dying.  His bike disabled the front derailleur and he basically had to ride it like a 10 speed for the last 20 miles.  I'm not sure the full story; perhaps he didn't charge it before the race or maybe he shifts excessively.  But whatever it was, I bet I'd be in the same position because I never charge any battery powered thing in my life.

Some of the reviews I read say the battery lasts thousands of miles or months at a time.  Which is impressive.

Rumor is Shimano will have a DI2 system for MTB out in 2015...

[SamSkjord]

You should get over 1000 miles on a 90 minute charge but there are quite a few anecdotes of sudden failure after only a few hundred miles so there may be a few iffy batteries about.
Chain Reaction are saying 01/09/2014 for Di2 XTR, I'll be waiting for XT for the bouncy given how many derailleurs I've gotten through.