Other than the weather not being ideal for much of the trip, Iceland was pretty great!
The best thing about Iceland is that the landscape is consistently between really good to astonishing. There are spots that are more naturally scenic than anywhere near here and it's just like ho hum keep it moving there (like you can't even pull over to take a pic) and the plethora of tremendous waterfalls is insane, again, with many being just something you drive past. This is the best waterfall (foss there) destination I've ever been to and waterfalls are my jam.
One negative is the wildlife is generally lacking. It is great for whale watching (we were up close to a humpback feeding for a good half hour) and there's also good birding, but not too much else (reindeer and artic fox in spots but we didn't see them). There are though a ton of sheep and horses to view with the beautiful landscape as the backdrop.