My MacBook Air reclaims memory almost continues...why?

Firstly, it is not recommended nor necessary to use third party memory management applications. Mountain Lion has an autonomous system which is very good at it's job.

In Activity Monitor you can see how much memory is in use. In the screen shot below, the green area of the pie chart is free memory and the blue is inactive memory. Essentially the blue area still holds information from recent usage and therefore can speed up re-use of this data, so a large amount of green "free" memory is actually a waste of capacity.

What is more relevant is the "Page Out" figure as this may indicate that data needs to be written out from RAM to the hard disk. Too little RAM may cause this to happen.

Since the MBA has SSD and this is fast memory too, having 2Gb of RAM is not the limitation it would have been with an older hard disk.

If your computer shows evidence of low memory I would suggest reducing the number of apps running at any one time, although even that is not necessary if the Page Out quantity is low or nil.

At the moment it is Fiplab that is choking your computer. It is the very act of reading and writing between the RAM and the hard disk that causes the slowness. The app is writing out to disk to "free memory" and make the pie chart nice and green. But much of the same information will then need to be written back to RAM again. You must get rid of Fiplab.

You could try some graphics test programs such as Geekbench, to see if your computer is good or bad compared with others. But I still do fine with a 2009 MBP albeit now with 8Gb of RAM but not the advantage of SSD.

http://www.primatelabs.com/geekbench/download/mac/

Here is what I get with the trial version, which is for 32 bit so may be a little inaccurate.

Is that with or without Fiplab? It would be interesting to see your scores for both cases. Perhaps too to research other people's scores for your model.

eg.

http://forums.macrumors.com/archive/index.php/t-427141.html

My first thought is that running a "purge" is going to clear out the inactive (blue) memory. This then needs to be repopulated, so may actually slow it down temporarily. Also, there are large variations in scores and newer models are blisteringly fast compared to yours and mine. Also, it will be interesting to see what effect 10.8.4 has on your MBA, if any.

Here is a comparison chart I found. I expect they are run with the 64 bit app and may be more accurate.

http://lucjano.wordpress.com/2013/04/02/pc-to-mac-macbook-air-buyers-guide/

Your welcome to my input. I think Geekbench scores relate mainly to the CPU chip, but other factors such as RAM also affect the user experience. I'll think about updating when the new MBP comes out. Blow the kid's inheritance🙂