Impact when moving from 2048 to 4096 bit RSA keys

Hi, I am trying to determine the impact of moving from 2048 bit RSA keys to 4096 bit RSA keys for a clientside ssl profile and would like to get some details of the impact when doing so.

1. I read that the TPS would drop to 20% of what we would be capable when staying on 2048 bit keys. Assuming unlimited license.
2. How much more latency would we have to face in the handshake process?
3. Is there a list of incompatible clients available? Something like 'Outlook 2007, Firefox 12, ...'
4. How much will the increased keysize strengthen the tls connection assuming we stick to the same cipher?
5. Any other sideeffects?

I did also open a F5 support case to this (C2910446 - Analysis of impact when moving from 2048 to 4096 bit RSA keys) but I was wondering if anyone from the community got some interesting ideas/comments to share.

Once I get a proper response from F5 support I can share here as well as I think many might be interested.

Cheers, Torsten