I am going to concure with Steve - I also do not live to write narratives (albeit, it is true - I am a bit verbose when it comes to writing them); I do them because what I am receiving in return is worth it. I AM a fast typist, and I am not one of those people that agonzies over every word either - especially when you are talking about technical style writing (following an established format, sticking to a certain type of information, little room for creativity - which basically is mystery shop reporting).
I find the cruises to actually have more free time then some of the shorter resorts. Yes, there is 'more' stuff to report on, but not commiserate with the additional days. Since I am one of those OCD types, I worked non-stop during the first half of the cruise so I was caught up and was able to relax during the second half. This meant that I did take half to almost full days off at times. It was not a "true vacation" in any sense, but like Steve's mine was easily worth 10K if not more. If doing a cruise like this means I can take two kick-a$$ vacations every year instead of just one, sign me up.
The one that was NOT worth it to me (which was actually longer in narrative length) was only 7 nights, which meant I had less time. It also was not worth as much (I could have purchased it all on my own for probably $3,000 total including my guest and airfare and transportation). The cruise ports were not interesting either (totally my own fault of course). I will admit that first one I did was more, "OMG it is a cruise and that is like the pinnacle of shopping so I must do it" and I did not really think out if it would be worth it. The second one was much more thought out. I knew what I was getting into and I ran the numbers and felt it was worth it to me.
In sum, I have had amazing travel experiences that were due to mystery shopping. I have gone some places I never thought I woudl go (and seen things I never thought I would see (some good, some not so good) - I hands down think it is worth it a few (or a hundred) pages.
And yes, you do get used to the narratives. Honestly, a 20 page narrative to me would seem short at this point.