Hi DavidSt,
While it might be tempting to try to 'cram' a lot of studying in these last few days, that is NOT a good idea. Taking a CAT every day is also NOT a good idea - you're far more likely to 'burn out' before Test Day than to actually experience any benefits. Since your GMAT is in 6 days, you could squeeze in 1 more CAT, but I wouldn't recommend it.
With a Q41, you're likely pretty good at the straight-forward 'math' questions that you see, but you're still making some little mistakes and you're missing out on LOTS of 'strategy-based' points (with many of them likely in DS). In these final days, your focus should be on light practice (with an emphasis on using Tactics) and working on your 'mechanics' (the physical way that you work through questions, note-taking, labeling, organization, etc.).
GMAT assassins aren't born, they're made,
Rich