OK well IB-E is certainly stronger but again it is by no means a question of plug and play at 2800. I know the board states this as max but it does state this is OCing and you might have to be good at tweaking voltages and timings to get this to work.
It's up to you of course and depends what you want to do with the board....benchmarking etc but I would caution against going that high for normal computing gaming etc. I'd say 2666 for a challenge and 2400 with CAS9 or 10 for great performance and no hassles setting up.
All this talking 16GB kits...if you want 32GB or 64GB then 2800 may be very hard to do...
If you could test some high frequency RAM with your CPU first to see if the IMC is capable (like friends etc) I would advise that...
Check the qvl for the motherboard