For me personally, I haven't done them because it's more of I don't really need to know; I already have a good idea of my subs capability through other tests (vid of FR of Hulk and Abomination scene, 10hz FV challenge, etc.)...and that's good enough for me right now.
The act of performing the test is really an irrational fear of mine...1) I have OM and I don't know of a 5sec sweep, 2) I don't have the equipment or know how for REW, 3) it is damn loud 4) And I am boosting the low end
Having said that, I would encourage everyone if you really want to know to do these tests. JT, especially in your case where you want to understand what you're getting below tune. Like bass said, the 5 sec burst should be fine.
A few years back when I had a pair of eD A7S-450s (put me at a 3.5 star ULF score to 12.5hz; no 10hz ULF score), an avs member came over with his PC and mic and we did do some sweeps of them:
I decided to not go any further because...well I was chicken basically because I was boosting the heck out of my eD's back then (for reference, they had a built in 17hz HPF that I boosted through!); and I was pretty happy with the 111db @ 10hz too.
As you can see, I have some nice room gain in my small room.