Kinesis GF_Ti V3 vs Whyte Wessex One?

I recently went through similar dilemma, I wanted something adapterable 1x, 650b /700c wideish tyres &/or di2 & as commuter full rack and guards, so
i considered the kaniesis, but the full bike costade me look elsewhere
As everything hangs off the frame I spent eyes debating what I wanted

Ruled out carbon as no rack/guards and scared of it getting knocked at wrong frequency in wrong place

Titanium hard to manufacture well I did consider J.ack leverage?? Or an Enigma escape even an Seven Evergreen but again costs put me off nearly £7k
I was tempted with Steel but in end went Aluminium.

I went for a Mason Bokeh but you could look at their Resolution

Re the long drop vs discs discussions - bear in mind that Shimano standard drop brakes (105 and above) will clear 28mm tyres. If you're mainly doing road riding do you need to go above 28s?

For mudguards there's also the new option from PDW to clear 28s. I don't know whether it will clear 28s plus mudguards on standard drops though.

If you do need long drops then there are options from TRP (RG957) or Velo-Orange. The Shimano long drops are good too - I'm well north of 100kg and they haul me up good enough with standard pads and aluminium rims. Not as sharp as a short drop brake but I ended up concluding that I didn't brake much (no commuting now I WFH) and long drops would be fine.

Get the right size GF_Ti and it will be the last road bike you need. From memory they do 7 sizes so you can really tune the fit on it, loads of flexibility there.

Personally, I got a huge amount of pleasure out of building my bike. Very similar to you, I cobbled together parts from various bikes and built up a Bowman Layhams with a mix of Tiagra & 105. Took me a weekend, learnt a lot, and now if something does break or go out of adjustment I know how to fix it. All the stuff I used to go to the LBS for (gear adjustment, bar tape) I DIY and the only thing I got them to do was chase and face the frame and cut the steerer.

The only thing against the GF_Ti for me is that the widest tyre it will take (in rim brake form) is 30mm. I don't foresee a need to go above that because I've got a tourer for rough stuff but that might be an issue for an N=1. Ultimately if you're happy with rims there's nothing this side of something with canti bosses that will handle fast road duties on a 32mm tyre.

I have the wessex. Great bike, altho unfortunately the mudguards are a bit rubbish. Unless you are hell bent on getting the 1x version, my vote would actually be to get the ultegra one (i work in a whyte dealer, I have experience of both, its just a nicer bike overall). Its incredible value, beautifully made and designed, and rides all day like a maniac.

You can test ride a Kinesis. Your nearest dealer can ask Kinesis to drop one of their test fleet at the shop for you to try. 

I can only speak for the Wessex, as I own one (albeit the 2x version) - but I'll try and give you as much info about it as possible! I also have 1x on one of my other bikes, so I feel I can make some useful(ish) comments on that.

My first ride on my 2x Wessex really surprised me as I've never ridden a bike like it (My other bikes a Canyon Ultimate). It felt quite short in reach, this was really easily solved by sticking a long stem on, which I promptly slammed (Dave Arthur did the exact same when he reviewed this bike).

The other thing that really stood out was how calm, stable and comfortable it felt, yet it's very nearly as fast as my Canyon. I could easily ride it all day and stay comfortable (in fact, I rode just over 100 miles on it and felt absolutely fine after - it just calmly rolls through the miles).

The stock tyres felt a bit slow, but I had a set of mid/deep section wheels with Conti GP4 seasons that were destined to go on it anyway - that made the bike feel quite a bit faster! The only other thing I do notice is it doesn't hold speed uphill so well (unlike my Canyon Ultimate - which isn't a surprise). The Wessex isn't a massively light bike, but I don't think it's trying to be.

The Wessex has provisions for dedicated mudguards (which is very nice as they don't require any hassle to fit, and they fit perfectly) and it still looks excellent and feels fast even with the mudguards attached.

There is absolutely no comparison to be had between long drop calliper brakes and disc brakes. I've had a bike with long drop callipers, they were no way near the performance of my disc brakes (rim brakes are excellent for lightweight race bikes to use in good weather though!).

The other excellent thing about disc brakes is you can stick a nice set of carbon wheels on and not need to worry about wearing the rims or losing braking performance in the wet.

As for the 1x, I use a 40t chainring with 11-36 on my CX bike (which I also use on road with road wheels), never had any issue climbing, but it does run a bit short at the top end - that said, I rode it up and around the Mendips (up Cheddar Gorge etc) and kept up 18mph with no issues. The Wessex has a 44t with 10-42, this gives you more or less the same gearing as 50/34 11-32. I haven't been bothered by/haven't noticed the increase in jumps between gears.

I use my Wessex as my year-round bike as well as my commuter bike and my not-so-good-roads road bike - it really hasn't let me down as it's very fast whilst being very comfortable and capable of tackling naff country roads.

In my mind, the Kinesis is a bit more of a "Sunday best" bike for riding when the weather is good and you want to do a short blast on decent roads (which may be ideal for you?). The Wessex is more of an all-round bike, but is also incredibly fast when you want it to be.