I have been using this software for more than 6 years now as my primary research tool when it comes time do market analysis or even just getting an idea about where your site is in relation with other sites (competitors).
It has always given me results which are pretty accurate but sometimes you might find some slight differences between what hits show up compared against actual data from Google Analytics - so be sure not too rely solely upon these tools! However if used properly can give excellent insight into how users interact within certain websites/pages etc etc. I like how easy it is for you guys (HitWise) are willing share your data with other people in order help them improve there websites or campaigns! The only thing i dislike about hitwize was when we tried using one from another agency which didn't work out well at all so thats why its not working right now but hope this helps solve issues if any!!