I can give you my opinion on the light bike angle, but not for heavier bikes.
I've gone from a 20 year-old steel-framed Mercian audax/tourer to a basic Orbea Gain (D50). I was worried it was quite a big step down in quality, but I was pleasantly surprised.
The Orbea Gain frame and equipment is plenty good enough (not as good as Campag on a Mercian, but still perfectly usable), and the disc brakes are excellent. The only weak point I've found is the wheel build quality, which I've remedied (I'm near max weight for the bike, so I'm probably the issue, not the bike). It has mudguard and pannier mounting points too - vital.
The weight is slightly up on a steel tourer, by maybe 2Kg, which is noticeable but not intrusive once on the move.
If you're reasonably fit (as your description says you are), then you'll be able to ride mostly with no assistance, and just use it for some hills. On shallow inclines you'll be OK under your own steam. For average to steep hills, you'll find you need to put maybe 30-50% in. For really steep hills like 14% (1-in-7) or similar, then you'll be putting 50%+ in, so it's not a free ride. Lighter people can put in less effort than me, of course - less to drag up the hill.
In terms of range, if you're only using assistance on demand, then you can expect much more than 60Km - more like 60-80 miles because you're only using it for, say, 10-20% of the ride.
The other reasonable priced light bike I'd consider is the Boardman ADV8.9, but it's a tad more than £2200. The two main positive differences are 1) it's a Fazua mid-drive rather than rear hub so the assistance follows your torque (pedalling effort) rather than your wheel speed, and 2) you can remove the battery, which is more convenient for charging. My wife has the Boardman HYB8.9 and I'd say it's slightly better designed than the Orbea, the Fazua system is impressive, so I'd say it's probably worth the extra. The only reason I didn't get one was that a cheap Orbea threw itself upon me.