Upgrade from CE 7.2 to CE7.4

Hello Everyone,

We have CE 7.2 SP09 portal installed.

We are looking for an upgrade to CE 7.4 SP05.

We have webdynpro, caf and bpm apps running on the portal.

I have gone through the following link which provides information about the migration of these applications to CE 7.4

[http://help.sap.com/saphelp_nw74/helpdata/en/e9/546e60777641509a5e0dc5cd05675b/content.htm | http://help.sap.com/saphelp_nw74/helpdata/en/e9/546e60777641509a5e0dc5cd05675b/content.htm]

From what i understand that the migration of webdynpro application would be done by migration controller inbuilt in nwds and only those applications which have not migrated will have to be repaired, rebuild and redeployed with API checks.

I would like to know how would CAF applications behave with this migration to 7.4? Will RFC's have to be reimported ? and what other impacts can be expected?

Other than this what precautions should be taken for migration to 7.4 ?

What are the likely or common impacts that we may possibly come across during the upgrade?

I came across another  blog too

http://scn.sap.com/community/netweaver-portal/blog/2012/09/09/lessons-learned-in-migration-to-portal-73-part-i

however I would  like to know more about possible application impact with  this upgrade.

Thanks,

Pooja M