Recently I took the plunge and splashed out on some new touring boots - the intention being to get a pair in the 1.5 - 1.7 Kg bracket which increasingly offers boots which will drive a big ski really well while not being too heavy for the uphill/climbing.
Last winter I was mostly skiing Dynafit Titans (big and beefy, but heavy), Head alpine boots (Raptor 120), and also spent some time in Dynafit's TLT5 Performance boot (super light, but a bit narrow for my foot even with some shell-stretching, and in my opinion missing a third buckle for good heel hold - full review here).
Seb at Sole Boot Lab in Chamonix took care of boot selection and fitting and I have now skied a pair of Dynafit Mercurys for a week so can offer some first opinions...
Weight. No matter what the manufacturer's blurb tells you, there is no substitute for getting the scales out - the results are as follows (for one size 28.0 boot):
TLT5 - stock liner + superfeet 'green' footbed: 1.253 Kg
Titan - Palau liner + Superfeet cork footbed: 2.087 Kg
Mercury - stock liner + Sidas footbed: 1.734 Kg
- just slipping outside the 1.7 Kg upper limit I had set, but still feel relatively light on the foot - only a big uphill day will tell though!
The Mercury is a 3 buckle boot - though the 40mm booster strap more than happily doubles for a 4th buckle on the cuff. The buckles remain low profile when closed - should be fine for climbing/boot-packing. In the open position the cuff buckle has a hinge point to enable it to sit closer to the boot shell - one of the downsides of the TLT5 was the buckle which stuck out a long way in 'open' position - check out the photo below to see the difference between the two:
Fit-wise I have a narrow ankle, high arch, and wide forefoot. The Mercury's fit out of the box is not bad for me, though I will need to widen the toe box a little for maximum comfort. For comparison they feel narrower than a Titan, but substantially wider than the TLT5
Conditions in the French Alps are a little scratchy at the moment, and most of my work last week was on piste (for once) so I haven't tried these out with any fat skis yet - last week I was skiing some Fischer Watea 88s and the boots were quite happy to really crank it out on piste. Good support, great heel hold, and a progressive flex pattern. The cuff height is similar to a Titan (see photo below - from left - TLT5, Mercury, Titan):
The boot sole length of 314 mm (for a 28.0) is only 8 mm down on the Titan (as opposed to 307 mm for the TLT5 !), so if you are swapping down from a bigger boot this should fall within the adjustment range of most tech bindings (eg Dynafit Vertical/Radical or Plum)
Downsides? During thermo-forming one of the liners developed a crease just above the heel on the instep - manageable this week as my heel has been locked down in ski mode, but could be an issue on the uphill and I will be heading back to the shop for a re-form or new inner. Apparently this has been a regular problem with the stock Dynafit liners!
Just like the TLTs, the lock mechanism for ski mode is integrated into the cuff buckle so a cover of some sort will have to be DIY-ed to enable light closure of the cuff without locking the boot for more technical climbing
So far I am really happy with these boots and can't wait to get out on some bigger skis and see how they perform...