Worthless IMO. Do NOT save UWorld for dedicated. I waited to do it this spring and it's the one thing I regret (took Step 2 yesterday). Do it now through rotations by subject and then reset it during your dedicated because there is simply too much information to wait. Step 2 is a very different test and should be approached differently. IMO the only resources anyone needs for Step 2 is knowing UWorld cold, and the Divine Intervention podcasts, but you need to know them cold.
The people I know that only did COMQUEST always under performed their prediction by a decent amount. I did the COMBANK comat questions over and over until I had gotten all of them right at least once, and then did all the other questions in the main Q bank for that topic.
For reference my average COMAT was a 116.