I must say, as an iPhoto user who currently is drowning in a mountain of around 30k photos, this salesperson did you a great disservice by recommending you get a standard platter external HDD instead of opting for the larger built-in SSD (or even a thunderbolt connected external SSD). iPhoto absolutely starts to crawl with enough photos and videos thrown at it, to the point where the speed of an SSD is all but required.
What makes it 'start to crawl'? I'm inexperienced in dealing with iPhoto and large datasets.
I'd agree more with you if you said the sales person did a disservice by not recommending the RAM upgrade as thats not possible to do after the purchase. The author can still upgrade the SSD from OWC in the future.
RAM isn't going to help in the case where you have a massive iPhoto library. I'm not exactly sure what causes iPhoto to perform poorly when dealing with massive quantities of photos, but it is nearly unusable on my 3.4 GHz i7 iMac which has 16GB of RAM unless I put the library on an SSD.
I use Lightroom instead of iPhoto, but I get the same thing when processing gigabytes of RAW files. Lesson learnt: split my library up (in Lightroom's case, a catalog) to minimise disk IO.
