I'm on my second Rise M10 XL. It's around 18.8kg and with summer tyres (dissectors EXO+s), carbon rim and XTR rear mech, it should be comfortably under 18kg. Being able to lift it onto roof racks, over stiles and gates, onto uplifts (don't ask) are important factors of ownership for me - I'm pretty feeble. I also love the acoustic feeling of the bike so I do keep a focus on the weight of it.
Therefore for me, bike weight is important. I don't think range is nearly as significant as 'range anxiety'. I often ride with the motor off. Life's a little slower, and a little less fun, but it's perfectly doable, even at the end of a long day. To move the weight nearer that of a 12kg Stumpjumper, and away from the 'barge against the tide' of a 24kg YT decoy, it makes a real difference to the feasibility of riding unassisted. If you can ride the bike unassisted, then suddenly ultimate assisted range has less impact.
Most of my rides where I've used all the internal battery, it's been timed to happen as I complete the ride, as I manage my speed and effort to match the pace through the battery. And invariably it's only flat because I forgot to charge it fully beforehand.
I've had a range extender for 20 months now. It's been fitted on just two all-dayer rides, but for both those rides, I finished with more capacity than the extender anyway.
Two other factors to my specific decision:
I ride on my own and with acoustic bikes and a Kenevo SL. If I were riding with a lot of fit Full Fat riders, I'm sure I'd be using the extender more.
I buy the bikes through the UK Cycle Scheme, so they're effectively 40% discounted, meaning, cost is less of a factor, as it's usually recovered in re-sale so I'm happy to spend more.
I hope that helps, I doubt it has in hindsight. I'm sure whatever variant you pick, you'll have an absolute blast.