Kona or Boardman

ADV 8.9 comes with 38mm G One tyres

I had the Boardman CX and sold it, really just because the shorter cyclocross geometry didn't suit me - if you're tallish it would be worth trying to get your leg over your choices and see how they feel.  

I've also had a Boardman road bike, and it was great - good frame and excellent component levels for the price.  Don't let the name put you off, they consistently rate extremely well in group tests, and Boardman bikes have won pro stage races and olympic gold medals.  I recently read Chris Boardman's autobiography where he talks about how the bike business got started, really interesting stuff, you certainly get the impression he knows his stuff and had a high level involvement with the design of the bikes, at least at the beginning...

I would echo the post above though - I hated the mechanical discs on the Boardman, really felt they lacked stopping power, and they fell off quite badly in the wet - I have other bikes with hydraulic discs, and even my budgetish hydraulic BTwin Riverside is in a different league.  

Nothing helpful to add on the Kona, my only experience of them is my wife's old MTB!!  Back in my old MTB racing days they were a well regarded brand, well built and innovative with geometry.  I get the impression they may have lost a bit of this brand "prestige" now though.  They spec out ok, but not spectacular.  

If they have any in your local store I would also try and take a look at one of the more relaxed geometry Boardman adventure bikes (Adv 8.9??) with hydraulic discs - check out the tyre clearance, it is likely you'll be able to get at least 28mm in there and maybe up in the 30's somewhere - with a carbon fork, that would probably provide a comfortable and capable gravel bike that would be decent on our crappy pot-holed roads at the moment as well...

If you are prepared to risk delivery, you could look at some of the online guys like ribble, who have steel, Al and Carbon gravel bike options startinf at less than a grand...

Wont buy a Boardman, out of snobbery-Jesus Fcuking Christ

I have both Boardman and Kona bikes, they both are good bike each with their own design faults, but nothing that cant be upgraded. 

Have a look at the Boardman ADV 8.9, it has hydraulic disc brakes which are far superior to any of the bikes you list,  they all seem to be mechanical disc brakes and are quite poor.  With a British cycling membership you can get 10% off from Halfords

My requierments for buying a bike are

Frame that has

mudguard eyes, disc brakes, wide tyre capacity(40mm ideal) QR 

Gearing

11 speed but 10 speed fine with 11-32/34 cassette  50/34 crank but 46/32-30 better(no one needs more the 48t.  Example 48*11 gearing will give you 53mph @ 140rpm cadence!

Bottom Bracket

Threaded external type- absolutely no other pressfit type.

Brakes

Hydraulic disc, nothing else

Trying to find a bike with those requirements normally pushes into£1000-1500.  But you save hundreds later by not having to upgrade parts because the bike has it all.

ive never ridden a boardman nor shall I, just out of bike snobbery, Kona however I have had a few and really like them as a brand.

Theres quite a difference in spec between the DL and NRB, the things that stand out for me are the carbon vs aluminium fork, Apex vs Sora groupset, 100+142x12mm vs 100+135x9mm wheelset. The 12mm is likely to be more future proof, however I personally use 9mm on all my bikes as Im not sold on the wider is better philosophy. The other thing with the wheels is the internal rim width 19vs23mm which will make a fair difference to tyre choice, but as you are intending to use it on fairly smooth hard surfaces then the 700c wheels would suit well.

Personally I have no problem with Sora as this is what Ive got on my diy gravel bike and it works just fine, but if it were my everyday bike id certainly want a higher spec like 105. The carbon fork is a personal preference, depending on which tyres you are going to be using and what terrain, but again I opt for carbon components where possible.

For me the question would be - do I want a robust winter road bike (DL) or a fun off road bike that I can ride to the rough stuff and home again (NRB).

If youve already got a decent XC / trail bike then the NRB is probably too simiar but if not then it may be an option to explore new type of riding like bridleways and blue/easy red trail centre routes.

Out of interest which year of Infinito do you have? The general blurb of the newer model says they take up to 32mm tyres, if this is the case, have you thought of getting an inexpensive wheelset with CX tyres on instead of a whole new bike?