That's rubbish. I went from a much faster cpu macbook pro 15 to a 2012 MBA last year and the difference in speed was immediately obvious. Even though the MBA had a much slower CPU, common tasks like word processing and browsing and email went much faster because of the much faster disk access and immediately noticeable opening speed.
I'm not sure what's up with the O.P.s post but frankly it's nonsense
Nope, nothing wrong with his post. Yours and quite a lot here are nonsense because they are only aimed at sequential read/write speeds given by a tool from Black Magic. This shows that almost everybody responding in this thread has little to no clue about I/O whatsoever. This leads to nonsense replies like yours.
If whatever you do on a computer is dependant on I/O (your disk) then obviously you'll benefit from storage that will allow lots of I/O. This can be a fast hdd or an ssd. The more I/O you have the bigger the difference will be. In reality this means that things like e-mail, word processing, browsing, listening to music, watching video, etc. will not benefit from an ssd at all. These tasks are not I/O dependant as can be seen by the mere existence of devices like iPods and sd cards. You need a class 6 sd card for video to record smoothly. This card gives you a whooping speed of 6MB/s. Any hdd you can get now can easily do that. A slow usb thumbdrive can do that. Typing won't go faster because it is limited by how fast the user can type on the hardware. Neither will applying text styles when word processing. The only thing you might see is a little speed increase when opening files and you'll see it with the larger files (things like a dvd image).
The reason why that tool from Black Magic is of little use is because of how big files are. Fileservers, database servers and the like will use large files and thus benefit from the high sequential read/write speeds. Any desktop/laptop that is used for things other than file/database server will not use large files. Those machines are more likely to use small files and thus ssd's aimed at desktop/laptop use are optimised for small files. These speeds are never mentioned by the manufacturer but will be pointed out in reviews as the so called random read/write speeds. The difference between the ssd in the 2012 MBA and the one in the 2013 MBA is big when looking at the sequential read/writes but might not differ when it comes to random read/write.
Another thing the use of an ssd can mask is lack of memory. Swapping is something that is very I/O intensive. Using an ssd for swapping is advisable, it makes it a lot faster. The only problem is that swapping is not always a good thing. Swapping may occur because an application has quite aggressive memory management (which is a good thing if the user benefits from it) but it is usually done because there is not enough RAM available. When using an ssd you could therefore see speed increased when you don't have enough memory because the swapping is faster. Increasing RAM solves the problem and costs you much less than an ssd.
CPU speed has nothing to do with an ssd. If the CPU isn't powerful enough you won't see any difference going from hdd to ssd.
When it comes to booting a machine the ssd is only 1 part of the story. There are many other parts that will determine how fast the machine boots. We've seen machines at work boot into Windows (that includes login) in 20 minutes. Putting an ssd in those machines resulted in booting into Windows in 20 minutes. The reason why it took that much time was simple: the machine was desperately trying to find our DC's on a network where it couldn't reach any of them. So did we benefit from an ssd? Nope as I/O wasn't the problem. However, if it wasn't for the ssd we couldn't have ruled out I/O-related problems.
TL;DR: you'll only see actual benefits from any ssd if you have tasks that are I/O intensive (moving dvd's around, virtualisation, swapping). If you don't (web browsing, emailing, office work) then the benefits you'll see are very slim and buying an ssd will result in disappointment (it is not as fast as others claim it to be). I've just seen too many people being disappointed with ssd speeds. Your workload decides if and how much you benefit from an ssd.
Try editing RAW picture from a full frame camera on Capture One Pro or Lightroom and you will see the difference. A big one I mean.
Only when opening the files and maybe when exporting but definitely not when saving your changes (it's RAW so it only stores the changes which is very small). Also, swapping can be something that is done in this case and thus it will benefit from an ssd.