Megatronics v3 vs Duet for Delta (would like 3 extruders)

Any comments on Duet vs Megatronics for Delta printer with 3 extruders?

I am in the UK so Duet was my first choice but it looks like I would have to upgrade with an expansion board for the multiple extruders (my long-term goal).
Would there be a noticeable difference in speed because of the different processors?
Any advice is greatly appreciated.

Thanks
Steve