Depends on what you are doing.
An SSD boots up in 15sec a hdd needs 3 times as long but how often do you boot the system once a month. Usually you just use Standby.
If run Apps like Browser, Office Word, itunes you see little benefit from an SSD. Yes the apps starts faster but given enough ram how often do you launch it fresh. Once it runs in RAM with the low and mostly asynchronous IO an SSD makes little to nothing faster. Reaction is mostly CPU bound. Though the Air Sinlge Core trubo should compare quite well in this situation.
For heavy use an SSD makes everything feel a lot faster though. Some IO heavy stuff like video/music editing, compiling or just using many little thinks in multitasking gets a tremendous speed boost. An SSD is the equivalent of a multi core CPU. You can throw lots of stuff at it at the same time and never have to wait.
For light usage though the benefits are heavily exaggerated. Unless you are stupid enough to constantly restart and relaunch you apps there is very little to no difference in speed. The faster CPU buys you more.
An SSD only helps were an App cannot hold enough of its working data in RAM. Once data is in RAM there is no difference.