I do not think you will ever know until you take the lab, all you can do is be prepared as best you can given your “personal circumstances” (time and $$$ being the big 2). Once you have taken it you can ascertain any of the following:
1. Lab is easier than I thought, either you pass or you gain a huge dollop of confidence for the next attempt
2. Lab is as expected, either you pass or again you gain confidence going forward knowing you are on the right track.
3. Damn, the lab is harder than I thought, I guess this one will be the hardest to stomach, and you gotta gain momentum and get straight back at it for the next attempt.
Add on to that the nerves and all the other “fun” stuff that make up the lab experience and I don’t think you can ever truly know if you are ready without having attempted it once. All you can do is be as best prepared as you can, there are plenty of mock labs etc that can replicate the level of technical depth you will need, I would stronlgly advice using at least one of these products.
If you wait until you feel ready … you will never go.
At Certification Science, we ask the students to take the lab within three months of completing the program even if they don’t feel 100% ready. We offer them the guarantee that if they do not pass, we will pay for their next attempt. Some students have “testidus” and simply need that little extra push to get them in the test. By putting our own money on the line, the students feel more confident in going into the test.
Most come out with a pleasant surprise, and the occasional student that does not pass usually rushes back in as soon as possible and passes on the second attempt.
Even if you do not feel 100% ready … go and take it! Remember you do not need to be 100% ready … only 80%! You can loose 20 points and still pass.