DAP doesn't install spyware, it even doesn't install adware. The ads are integrated in to the GUI of the program....
I use the payed version and are very very pleased with it. I tried other download accelerators aswell before bying and my topchoice is DAP...
Btw, a download manager is not a download accelerator. Both are different things... A download manager can be a download accelerator but not neccesairly...
Oh, and I don't use DAP as a download manager (it can be used as that though). But I use it for it's main function, accelerating big downloads. This means, it don't use the integrated options for MSIE or other browsers that will take over the downloads (like a download manager does)...
also see:
Downloads accelerators site