That is where i don't know. I would google SSD vs regular HD and see if they have some specs,test,and all that to see if it is really worth it. It is really hard to tell the difference.
However SSD will most likely outlive regular HD due to the SSD not having any moving parts inside of it. And of courses have a faster seek time due to having no internal moving parts and flash memory.
However it is rather expensive and only for the hardcore enthusiast. I picked out some key points of SSD vs Sata HD.
-"Notice that having six hard disks does improve seek performance noticeably over a single hard disk, but the single SSD still dominates..."
What this is saying is that even if you had 6 HD (which you can't in a laptop but a desktop) the SSD is still faster than 6 SATA hard drives in seek time. This is why typically SSDs can boot faster than regular HD.
-"the SSD has such an advantage in seek time, it can show with an overall improvement measured in seconds to load a very large application"
If you open a large file, ur HD has to read multiple files in order to launch it. SSDs can read them quite fast and this leads to significant load times for LARGE applications.
However, in block transfer speed conventional HDs actually dominate SSD but only when you have 6 SATA HD in raid.
All this information of comparison was found here:
SSD vs. SATA RAID: A performance benchmark
My point is, I really don't think it is worth spending that much money unless you are doing some intensive stuff on your mac. If you want to spend the money on a small but fast HD and have the money to do so, then by all means do it. But I say go the route of a 2.5 internal SATA 500GB 7200rpm HD. You will be satisfied.