This right here is one of the prim reasons why I will go to 6800 over my current 5700. The front shifting is crap. It will shift every time but it requires quite a bit of effort to get it done...and not fluid in the slightest. Rear shifting on the 5700 is fine, I have no complaints there.

What crankset are you using? 5700 front shifting is fine in my experience. FSA chainrings or Shimano have both worked well. I will say that it is a little smoother with Shimano though. I've never felt that effort to shift the front or the throw is excessive. My only petty gripe with 5700 shifing is the rear actually. Kind of mushy, but otherwise works just fine.

I'm using a FSA Gossamer crank with Praxis chainrings. With stock rings the shifting/crank feel was total crap. Well...I didn't notice how bad until I added the Praxis rings. My gripe isn't the small-large transition, its the effort it takes to get the derailleur to move. The action requires force and is "gritty-chunky" compared to the smooth 5600 I used to ride. The large-small transition is flawless and immediate after the "pop" of the shifter is felt. It's the force required to get it to go small-large.

With the rear, my only gripe is the double shift...which has never been all that great no matter how much I mess with it. I can get the single shift positions pretty dialed in...but that double hop is pretty lousy.

I'm waiting for 13 speed.

Interesting. I've not had that experience with the "gritty-chunky" front shifting, as you describe it. I will agree with you that the shift feel of 5600 is better than 5700, just slightly though, at least for the rear.

I think quadrings are the future.

Are double chainrings on 5700 further apart than on 6700 cranks?

Don't think so, why would they be??

Long Term Review: Shimano 105 Road Bike Groupset

Shimano’s Hollowtech II cranksets have proven plenty stiff while remaining within spitting distance in weight to mainstream carbon cranks. The functional change with this group was a bit wider spacing between the chainrings to improve clearance when cross chaining. For a group that’s likely to get spec’d on more entry level and “enthusiast” bikes, that’s a good thing. For more performance oriented cyclists that shift the front chainring more frequently, the good news is it shifts up and down the rings quickly and easily, even under hard effort.

Interesting.

For now, as it seems, I'll score used 5700 groupset next week for a reasonable price. With little luck I'll be able to sell all my old parts and even earn some money out of it, or at least be at 0.

OT: Silly how in Europe all this 80s and early 90s Ultegra and 600 parts still hold their price, not to mention Campagnolo.

I will need to buy a new front deraileur and BB shells since my frame has italian threaded BB and braze on, and the 105 groupset i'm taking without the band on front derailer and without the BSA BB.

Just checked chainreactcycles, Ultegra Hollowtech II BB is 20euros, that's nice, 105 BB is 3 euros cheaper only. Will opt for Ultegra.