Hello,
I have the vertex 2 - currently it has been solid for me for 3/4 of a year now (there were bugs in the firmware which have since been rectified with firmware updates). For $100 IMO is a good deal for a 120GB SSD, I paid over $300 for mine when it came out.
After getting the SSD, my boot times and programs opening have become much quicker, it doesn't affect gaming speed (with the exception of course of quicker loading of levels, and installs).
I'm unsure of the pyro's history but you will be paying more than $1GB versus the $100 Vertex 2. The pyro may have much better reads and writes (and random ops by about 2x), but the vertex 2 is fast as well - and it would be hard to tell the difference between the two without doing synthetic benchmarks, not to mention the sheer fact of upgrading to an SSD from a HDD is just massive.
Consider this - HDD's (7200RPM) usually have a seek time of around 7ms-and can go higher depending on data usage. SSD's usually have a "seek" time of about .07ms (can go higher or lower of course), so automatically it is approxiamtly 100x faster reading and writing informaiton.
Another thing to consider as well is - do you need more storage, or could you do with more "responsiveness" from an SSD?