Well I would go to Halfords and buy a Boardman - more bangs for your buck because they are made by Halfords, who sell a lot of bikes.
No Boardman is rubbish because Halfords dare not defile the name. You can spend £2000 but also a third of that.
I would say what I intend to do with the bike and the limit of how much I was willing to spend. That determines the geometry and the specification. The "salesman" at Halfords is often the mechanic who fixes bikes. They know what they are talking about. They are usually keen cyclists.
Halfords will have lots of models in stock to try out for size.
That is how I bought my first two Boardmans. I kept them for 9/10 years and never regretted the purchases. I sold them both for 40-45% what I paid for them earlier this year. I had done 10,000 miles on the road bike. It owed me nothing.
I bought a new Boardman (ADV 8.9 "Adventure" bike) this year for when I don't want to take the Bianchi out in the rain.
Cyclists tend to look at other bikes on the road. I have done 30 + miles today on errands and I saw a lot of Boardmans.