Heathrow transfer
 

I've read in other threads that the inter-terminal transfer at Heathrow might be difficult because of poor signage and directions. How about time?
I'm getting off a BA flight (arrives 15:30) at terminal 2 then getting on a CX flight (departs 18:25) at terminal 3. Assuming I need to get the luggage, clear custom and check-in again, would I make my flight?
Please advise! Thanks.

You have 4 hours, it should be no problems. I've never had a problem with signs at Heatharow, they are fine. Terminals 2 and 3 are connected (but are you sure your BA flight gets into Terminal 2, most BA flights go to Terminal 4, but not all of them).

it's a code-share flight with Iberia that flies into terminal 2.

If it is a code-share flight and you are all on one ticket, BA should be able to check your luggage all the way through to your final destination. Ask when you check in and make sure the luggage tags reflect your final airport destination. They should also be able to give you the boarding pass for the next flight as well. This way, you can just go to your connection terminal. 3 hours is plenty of time.

I've never had any trouble with Heathrow. The signage is OK and it was obvious what you needed to do. Before you land, look in the back of the flight magazine on BA which shows detailed airport layout maps.

Also ditto the suggestion, are you sure you can't get your luggage checked all the way thru to your final destination?