IIS Performace Issue (Gzip / PDF)

I have a web based Application developed in .NET and backend Oracle10G. Majority this application has dynamic pages. It takes very long time to open the pages and do the data entry.

From networking side i have IP/VPN to different locations. Presently IIS compression is not enabled. Do you feel enabling Gzip & deflate performace will increase ?

I have also heard abt incompatibility between dynamically generated PDF & Gzip.