I have both so I'll lay out the differences that I notice and then give my opinion.
The MBT has a wider trigger face .305 compared to the SSA .285.
The face of the MBT is flat and the edges are almost squared off versus the SSA has a curved face and the edges are rounded
I prefer the feel of the SSA on my finger than the MBT
Obligatory ARFCOM feet picture
I would say that trigger pull on these two is a draw. Both have very clean breaks, no noticeable creep, and predictable.
Between the two, I cannot feel the difference that would make the SSA worth buying over the MBT especially when you factor in that you can buy two MBT's for one SSA.
I prefer the SSA-E over my MBT's but barely, and I've slowly graduated towards MBT's as I cannot get over the price compared to the slight advantage.
Buy with confidence when getting the MBT