Hey, I'm sure a lot of commuter-folk run with internal hub over cassette/derail. I was considering such but concerned over getting the rear wheel off to change flats.
I can change a flat pretty quickly on derail setup but I've never tried with hub wheel.

Question: is it easier, harder, or about same for changing out a hub wheel in comparison to derail setup?

IGH definitely will took more time than derailleur because IHG got nuts and chain tensioner to remove, but not much when you get use to it.(Practice for 2-3 times and you'll be ok.)

Depending on the IGH the time involved to remove the rear wheel will vary but the job is still easy.

yes,what they said,mine needs a 15mm and a 10mm wrench,but i have done it so many times(50,00 miles on this bike).You may not need to take the wheel out to fix a flat.You only need the innertube showing.

Mine takes a 15 mm wrench and about 5 minutes. Once you get used to it, I don't think there's any noticeable difference in difficulty.

IGH with hub brake is a bit more difficult, only because you have to futz around with the torque arm fastener and another cable on the non drive side. If you're running IGH with disk or rim brakes, I'd say it is about the same, except for using a 15mm wrench to release and install.

Thanks folks, makes sense, I guess the trick is to just be quick with the wrench, which isn't a big deal.

Another question from Mardmakarm's comment: why do you have to remove the tensioner? Wouldn't you be able to pull the chain off without removal once the wheel was off.
Or why would a IGH bike have a tensioner (I thought they ran one ring in the front, usually)?

some IGH's that roll with disc brakes use a chain tensioner to maintian chain tension because disc brakes don't work with horizontal drop outs. other solutions for providing chain tension with an IGH/disc brake combo are sliding rear drop outs or an eccentric bottom bracket; both are more elegant solutions than adding a chain tensioner.

I have four IGH bikes, all Shimano, three with chain drive trains and one with a shaft drive train and I can honestly say that it takes me less than 5 minutes to remove the rear wheel(s).

It's only as difficult as a derailleur wheel with a nutted axle. Unless you have drum brakes, all that needs doing is loosening the axle nuts and usually releasing the gear cable. Nothing too complex really.

Chain tensioners are used for retro-fitting IHG onto vertical dropouts OR by lazy manufacturers who use a bog standard hybrid frame for their IHG model.
You shouldn't buy a new bike with one.

You wont get a racing-speed wheel swap with an IHG but its no big deal. There is a trick to unhooking Shimano cables from the hub, just a small twist and the nut pops out of the cassette arm.
I like my Alfine hub and wouldnt go back to derailleurs for everyday city riding.

...OR the bike is equiped with more than one chainring up front and some form of front shifting, in which case it is perfectly acceptable...

After you've done it twice, you should be able to do it in about two minutes (although I don't know how it works with chain tensioners). But practice at home, and make sure that you have an appropriate 15mm wrench - I carry a 6" wrench because the extra leverage over my 4" dogbone wrench makes a difference.

I own a bike with an IGH.

I do find that removing the IGH back wheel is a lot more difficult than with my derailler bikes. However...um...let me put it this way. If I practiced every day at it, it would be a little more work (and as other people said don't forget that you need the wrenches) but not a huge deal.

The real problem is simply that I forget the steps I need to go through to do it, so when I go to do it again I can't remember how I did it last time. Whereas I've taken the back wheel on and off enough regular bikes enough times that I know how to do it. Well...lol...sometimes I still have some issues with getting the wheel back on in the right place with the chain.

Those are my thoughts at least...note that this does not stop me from using an IGH on my winter bike though.

Civia Cycles also has videos on how to do it so you can see for yourself -

This one -
https://civiacycles.com/civiaMedia/Al...bleRemoval.swf

Then also this one -
https://civiacycles.com/civiaMedia/Al...eelRemoval.swf

To remove the rear wheel. To put it back on again, it's this one -
https://civiacycles.com/civiaMedia/Al...bleInstall.swf

Then this one -
https://civiacycles.com/civiaMedia/Al...eelInstall.swf

For whatever reason I always find taking the shift cable on and off to be a lot more annoying than it looks like in the video...kind of like how with a derailler putting the rear wheel back on in a video often looks easy but in reality I always end up screwing around with it trying to get the wheel back in the chain in the right position, lol.

Rohloff makes a QR version CC, and a solid bolt TS version ..

On my Brompton, with S-A AW3/BSR hub, I keep a 15 mm open end wrench
with the patch kit.

have a fairly short reasonably light weight one... a 6" crescent/adjustable wrench
would do as well..

I don't think the 4" opens far enough..

You can make wheel removal and installation a bit easier by using Axle Releases.

Old school wingnuts.