Look at the individual scores and not the overall. It is possible that it is just the SSD that is making the difference, but it is possible that there is a problem somewhere else in the chain. Maybe your ram isn't doing too well. Maybe your gpu is bottlenecking. Maybe there is one section where he beats you a lot and it makes the overall score go way high. Look through it and see what you come up with.
Well, how do you do in games compared to this friend of yours? Is it a similar story to the passmark deal or is in more what one would expect with the specs (290 vs 660)?
My graphics card is the saphire tri-x r9 290 (stock overclock with no tweaking), ssd is just an ocz agility 3
i use passmark as a means of diagnosis rather than just for willy waving contents (although that is fun too).
It has helped me to spot problems quite a few times.
the best use of it is for like for like comparisons of hardware on the passmark website (e.g seeing what other 8350's typically score), once you know what the average range is that your piece of hardware (cpu, gpu, ssd etc) falls within you can tell quite easily if something isnt performing as it should.
When i build pc's for other people I always run a set of synthetics (passmark being one of them) first to see that the machine I am handing them is performing within acceptable parameters across all the components.
I judge it to be an extremely fair testing method from my experience.