Firstly, you need to consider if you can do 5 consecutive 24 mile commutes week after week in all weather conditions. It can be a trying and miserable experience on a bike. I am pretty fit and regularly run 6 miles 3 x a week, swim and do a few triathlons. After 5 consecutive commutes (20 miles each) on my Kalkhoff, I don't want to cycle again for a few days. This is because I've spent more time than I'd like on a bike (boredom), or I've been soaked every day. And, you can become tired even though the bike assists. Consider these things before deciding to comit to biking long term and spending a lot of money.
I've had a Kalkhoff with a Panasonic crank drive and an 8 speed Shimano hub gear for the past 6 years and it's been virtually faultless considering the use it has had. It's done a lot of miles (17500 ish) and I think it's had two new sets of sprockets, two new chains and numerous brake pads which is a remarkably low level of maintenance.
I know that Kalkhoff no longer use the Panasonic motor (a shame in my opinion) and use their own Impulse drive (again a crank motor). I have no idea what the Impulse system is like to ride or how durable it is, but my experience of Kalkhoff products is one of quality and reliability. I would hope this has been carried through to to the Impulse system.
Another thing to consider is that hub motors tend to have wires running all over the frame joined with kettle plugs and multi-pin connectors, all of which are susceptible to water ingress. With the Panasonic and Impulse motor crank drive, battery and motor are virtually all one and everything is sealed. Mine has been virtually submerged several times without a problem and I think that flecc actually did submerge his.
The Panasonic battery is good. 17500 miles, six years old and still ok for 26 to 30 miles per charge. I'd hope that in the last 6 years, Kalkhoff have improved this with their Impulse battery.
Schwalbe Marathon Plus tyres will give you high puncture resistance. I've never had a puncture.
You will need to learn how to clean and lubricate the drive (chain and sprockets) and maybe change brake pads. Magura hydraulic brakes make the latter easier. Having a bike shop do these tasks isn't cost effective.
My original Kalkhoff's motor has failed now. I paid (£1500 retail) for the bike less cycle scheme, so it came to about £1100 and I've probably spent £200 on it. £1300 for 17500 miles will do for me. Whilst I've been on this forum, I've witnessed several people purchase cheap junk in the belief that they are saving money only to end up replacing the bike at a total cost equivelant to something like a Kalkhoff. Then, they are still left with junk. Also, price tag is no indication of quality.
What I think is absolutely essential for you to do is (1) decide if you can cope with that daily commute and (2) visit 50 Cycles if you decide that you can, AND that you want to buy a Kalkhoff.