I think I'm right on the edge of a Large for those GTs.
At 5'10 I am probably a more natural medium on the chart. I'm longer in body and shorter in leg so in theory a large might work if the seat tube isn't crazy long.
Don't suppose anyone my height is riding a Sensor who can offer a view as it looks bargain tastic?
My nephew bought one in Large because that was a good price. He's 5'9". He wishes he'd bought a medium.
I've been wondering how I could engineer a swap with someone who's in the reverse situation and would prefer a Large over Medium. It's still in VGC, doesn't ride that much.
I got a Chisel (110mm/130mm) as well.
A lot of XC bikes now have modern geometry with 65/66 degree head angles. Does all local riding with XC tyres on. Beefier tyres for any weekends away.
It just feels faster and more fun. Tallboy might be similar.
Once you get up to 150mm/160mm which is where a lot of trail bikes are now, might as well get an ebike for getting more laps in on the fun stuff IMO
It's not necessarily the amount of travel but the quality of the travel. And there are other things that should matter. Build quality, cable routing, functional design, QC, ease and cost of maintenance, frame storage etc ..
I'm afraid this all points to a Tallboy. It's not really a XC bike, too heavy and burly for that, particularly with a 140mm fork. My XL CC is 3,250g so solid in particular in relation to the relative simplicity of the kinematics. My riding pattern is identical to the OP.
I don't really get the off the shelf option either. The Merlin price headline is good but check what you get in terms of drivetrain and wheels.
It's actually cheaper to buy a used frame and build yourself. But you lose the warranty...
The previous gen Stumpjumper (non-evo) works pretty well in the Peak for me. Happy medium between mile munching xc and capable on most trails if you don't try and ride like Loic Bruni.
I have a Bird Aether 9
Love mine on a lyrik in ML size. Handles anything I'd throw my 160mm eeb on 38s down but just feels so much nicer to ride. Just wish I was fitter.
Leftfield option - and it would be a tiny bit of faff to get to the UK and would need to be built rather than bought to get under the £3k budget - but I imported a Canfield Tilt frame + CCDB Air a couple of years ago, built up with some 130/160mm dual travel Lyriks + standard-ish wheels/brakes/groupset bought at sales in the UK and it is superb. Not the lightest bike in its class but I reckon it would be top 3 in both climbing and descending. I previously had a Banshee Prime and have borrowed mates' Pivot, Trek, YT Capra, etc. and for my money it's better than any of them.
For reference my riding is a mix of local woods type e.g. Pitmedden, Blebo, Ochils plus trail centres e.g. Laggan, Comrie, Glentress
https://mbaction.com/long-term-review-canfields-tilt-pro-offers-timeless-trail-excellence/