Difference

You can directly save the document as a PDF file. No need to download extra add-ons. This feature comes bundled with open office.

But in Open Office Spreadsheet i find Shortcuts used in MS Excel is not usable. 
 

Being an Open Source Enthusiast, this is very hard for me to say.. But..

Open Office (OO) is a terrible app. MS Office wins hands down.

OO Developers should have taken lessens from Firefox Mozilla. :-(

Agreed with Ramakrihna. However, cost matters. You cannot purchase so many MSO licenses. Therefore you have to keep a few of them to be compatible with VAT and other department online filing that do not even work with MSO 2007.

In an office with 10 computers best is follows:-

1 PC with MSO 2007 + Word and Excel 2003 Installed. + OO

3 PCs with MSO 2003 installed (if you still have it) and MS Read only Viewers for 2007 Documents. + OO

Rest of the PCS with OO and MSO 2007 Viewers.

This way Government work will not suffer and one can send PDF files in lieu of .doc

agree with sunil

OpenOffice is the open-source version of Sun MicroSystems' StarOffice productivity suite, but you'll be forgiven for thinking it looks an awful lot like Microsoft Office 2003. In fact, OpenOffice may feel more like the MS Office you're used to than Office 2007, as the former has chosen not to emulate the controversial ribbon interface that defines the latest incarnations of MS Office. OpenOffice's pitch is that it can do virtually anything that MS Office does, open any MS Office file (including the docx 2007 versions), and export to any MS Office file type -- but for the best of all possible price points.

Open Office 3.1 includes the Write word processor, the Calc spreadsheet, the Impress presentation creator, the Base database program,and the Draw graphics application. This review will focus on the first three, as that's where most users' office application works is centered, and it's where most MS Office alternatives compete for your software dollars -- even if many of the competitors are available for free.