I generally hate using 3rd party controls/libraries in applications, as you become tied to that vendor, their updates, and future support. Sometime you have no choice, as the problem domain takes too much expertise to write yourself. That said, after using your EO.Pdf libraries for just a couple days I'm very impressed, especially with your documentation and responsive support. Your tools and registration/licensing are also very developer friendly. I once stopped using an Excel library because every time I changed machines, I would have to get the developer to re-register the library for me so I could compile/deploy my code. Made it very VM unfriendly. Needless to say I drooped that library as soon as I could, even though it worked well otherwise. So with that being said, have you considered developing some libraries for...

*zip file manipulations?
*Excel manipulation, DataTable to Excel import/export?

There are many libraries out there that support the above, some are free, but I'm sure your team would build an easy to use product that would trump those (assuming you have the expertise/resources). I'm using some now in fact, but I would consider switching if the quality/ease of use is similar to your other tools. Just a thought. :)