As a 30kWh Tekna owner I would say get an Acenta unless you really want some of the Tekna features. If I was buying again I would probably get an Acenta and pocket the difference. (I wasn't able to test drive either before purchase - I took a punt during the lockdown last year buying remotely from a trusted seller)I do think I will wait for the right 30kwh car to come along, the decision now really is...is the Tekna really worth the premium one has to pay over the Acenta?
What is the difference in trim? Leather, surround cameras, heated steering wheel and rear seat. Anything else?
The Tekna leather I have seen doesn't seem to wear well and for a run around, maybe fabric trim could be better, cooler in the summer and warmer in the winter.
Heated seats and steering wheel is nice, but I find the drivers Leather seat a bit hard and uncomfortable without some padding and the heater is good enough in the car that I don't really find myself wanting to use the heated seats much anyway. (Although I do use the heated steering wheel in winter)
Birds eye camera view is genuinely useful (especially when there are no parking sensors) but not a reason on it's own to choose a Tekna. Can't comment on the Bose subwoofer as I haven't heard a Leaf without it. Stereo in the Tekna is "OK" after a bit of EQ adjustment but nothing impressive, so I guess the Acenta will be "OK" with less bass and a little bit more room in the boot...
The big problem with the Tekna for me is the wheel size - yeah the Tekna wheels look much better than the Acenta wheels, but the 215/50/17 wheels just don't ride very well, I find the ride pretty harsh (especially on crossclimate+ which made the ride worse) and although I haven't driven an Acenta I'm sure the ride would be more compliant with the smaller 205/55/16 tyre size. Also tyres for the Tekna wheels are pretty much 2x the price of those for the Acenta wheels and there are far fewer tyres to choose from in that size. (It's an uncommon size) So if you do a lot of miles or get a lot of punctures a Tekna is going to cost you a lot more in tyres.
If you have a fixed amount of money and the choice is between a 30kWh Acenta or 24kWh Tekna I'd get the 30kWh Acenta any day as that extra 25 miles range is absolutely worth it while the Tekna differences are mainly perks/toys and you get penalised on the ride quality and tyre cost front.
Try to take both an Acenta and Tekna for a test drive to see how you find the ride and seat comfort of the two. I wish I'd been able to test drive last year but it wasn't possible in the lockdown and I needed to change cars urgently so I took a punt. Apart from the tyre size/cost/ride issue and having to pad the drivers seat slightly I've been very pleased with the car, however in hindsight I think I would have been perfectly happy with a similar condition Acenta, perhaps happier if the ride was better than the Tekna.