There’s a nimbus 36" ($515) and a nimbus 36" with an airfoil rim ($599) on unicycle.com. I understand that the more expensive uni is going to have a stronger rim, but how much stronger. Given the price of the uni, shouldn’t the rim be strong enough already?
Will I be able to ride the cheaper uni with its standard rim and still go up and down curbs on my ride to work? The maximum drop would be no more than 7 or 8 inches.
The airfoil or alloy rims are much stronger and lighter than the single walled steel rims. I highly suggest them. They will stand up to abuse better, stay true longer and last longer. That’s the reason UDC is always out or nearly out of them. The $599 nimbus also comes with alloy crank arms which are nice. I’ve ridden my 36" nimbus with the good rim over 900 miles and on several off road trails and its fine. I wouldn’t trust the standard rim to go off a few dozen surbs in town without eventually becoming bent or noticeably out of true.
I have been riding the cheap steel rim for months
It has stayed perfectly true in very mild off road riding, and curb type roll offs such as you describe, under my 190 lbs. That said, the air foil is lighter and stronger, very popular.
I would advise against buying either right now though. Read the new Coker thread. Coker is going to release a new 36 this week ! It’s not often we get a new 36. You should wait a few days and check it out. 
where do you find the coker thread?
keep in mind the new coker is also 48 spokes instead of 36. On a humorous note, “next week” has been the last 6 weeks…but I dont blame them for wanting to get it right even if it takes time
So far, released images of the new coker weren’t very impressive to me. I can’t say anything for certain, but it looks like it’ll turn out to be really heavy. The too many spokes, the twin-fork frame (angled in such a way that it doesn’t provide any advantage…plus more weight); but true, I don’t have the whole picture yet.
Also, keep in mind that the expenses on the cheaper N36 are generally not for an upgrade on the rim, but for upgrades in shear design (particularly the frame, which absolutely does stabilize turns by displacing some weight in front of you, pulling the unicycle back into its straight path once you disengage your lean). I’ve ridden my deluxe N36 about 2,000 miles since January, and the wheel is still true, the tire is unscathed, and the cranks are correctly aligned.
I’d say it would be wise to check on the new coker when it’s released, but I’d still recommend the N36 deluxe.
you have a bent spoke 
It’s ok, I love her for her personality…
That’s fairly dissappointing. For 500 bucks+, I’d like to think the rim would have been strong enough to take curbs. I understand it’s an expensive frame, but you can’t seriously tell me they couldn’t include the stronger rim.
I don’t want to bash the nimbus because I have never had the chance to ride one. But I will most certainly wait to see the new coker first, then I’ll look into a new uni. Speaking of, that new coker frame looks hardcore.
Actually, the stock rim is plenty strong enough when used with the extra-wide hub. I had one for years that plenty of offroad abuse.
But, the airfoil is stronger, truer, and most importantly, lighter.
Don’t assume the new coker frame will be heavier
I’m sure they will use thinner tubing, so we must wait and see. As you can read in the "new coker " , thread, I linked to above, near the last page, is the latest ad from last week. They promise “the full Monty” next week (this week now). So I think it should be today, or tomorrow.
see this is posted pics of the new rim
I do agree with some of the above. The standard rim I rode was on a narrow coker hub which I’m sure added to its weakness. It would be much stronger on a UDC super wide hub which is what the nimbus ships with