I decided to do a series of 4 tests.
1. 2-speed lactate test
2. 1 minute peak power test
3. 2K test
4. 6K test
There is a specific purpose for each of the tests, and they focus on different things.
1. The 2-speed lactate test
ref: The Science of Winning, Olbrecht
For this test you do the same distance twice (I did it as a 1K). The first time at a power around your lactate threshold power (6K pace), and again around your estimated VO2Max power (2K pace). You measure you lactates after each piece. By plotting these lactate levels and powers, you can compare both your aerobic fitness (by horizontal position of the line) and your anaerobic fitness (by the slope). It is most useful to use to compare to prior results for the same athlete to see if you are getting fitter or less fit. The good things about the test are that it is not horrifically taxing, and getting the test power exactly right is not necessary for an accurate test result because your lactate level will be corresponding higher or lower along the same line.
The results of this test looked like this for me:

2. 1 minute Peak power test
Ref: Rowing Faster, Chapter 6.
This test is a bastard. the instructions tell you to row as hard as you can for a minute, but there is a devilish twist. You are not supposed to pace yourself. You are supposed to take every stroke as hard as you possibly can, and the point of the test is to track how you power output peaks and then fades as your muscles slowly seize up. It is an adaptation of a "wingate test", which I had never heard of or done. The point of this test is to provide an objective assessment of your peak power output and ability to sustain power anaerobically.
It took me three attempts to get through a minute, and it obviously impacted my results. I intellectually knew that it was going to be a painful and difficult experience in the last thirty seconds, but it still took me by surprise. I plan to do a repeat of this on fresh legs next week.
Here are my results for my first failed attempt and the one I completed:

The good news, I improved my Low Pull by a few seconds (from 700W to 770W). Just like the 2 speed test, this provides a baseline for me to compare to after I have done a block of power focused training.
3. 2K test
Simple as can be. Row 2K, record the time. It's a half decent proxy for VO2Max power. I did my trial today, with these results:

I had a little crisis around 800m when the going got tough, but pulled it back together. I'm a long way off my PB (14 seconds), but I haven't done any erg based sprint or power training to speak of recently, so I'm reasonably happy. (It also put me 18th in the rankings for my age group)
The other thing a 2K test is good for is to provide reference pacing for lots of training pieces.
4. 6K
As simple as the 2K. Row 6K record the time. It's a very good measure of aerobic fitness. Anaerobic abilities won't help you here. 6K also provides a useful pace marker for long intervals. I'm planning to do this on Sunday.
Once I have all the numbers, I will use them to figure out how to balance endurance, lactate tolerance, sprint and power training leading up to the Crash-Bs. Then I will redo the tests after the Crash-Bs to see if the plan worked.
What do you think? What testing do you do? How often do you do it?