Why there is many sets in m4a format ?????

I just wanted to know why choosing m4a format for sets...  i see many sets uploaded in m4a, many UMF sets from WMC !

Personnally i think that mp3 is still the best because one 1 thing :  Its easy to use because every software is able to play them as well as any devices like Ipod or any other ones

m4a doesn't allow that... i have to play them with VLC media player, they can't be played by regular Windows media player that many people have and they also can't be played on my samsong player that i bring at the gym

Poor choices for me... i wish that everybody just stick to mp3

I don't know too,but you can always convert you m4a sets to mp3

When working with a band limited sound @16 kHz, such as transmitted over FM radio channel, one does nod need to use an encoder at bit rate more than 128 kbps. (Yes, no need to use mp3@192 kbps)
When working with a band limited sound @22 kHz, such as a CD rip one could solve a simple optimization problem.
One needs to choose between mp3 encoder and m4a encoder, under a restriction – a bit rate no more than 192 kbps, and using a criterion for a choice – maximum of the preserved signal bandwidth.
The solution of the problem is m4a encoder. It can preserve 20.1 kHz signal bandwidth @192 kbps, while an mp3 encoder can preserve 18.5 kHz bandwidth.
As to me, I work with 22 kHz bandwidth sound and have already solved this problem. So, I use m4a file format under above conditions

As to conversion to mp3 file format at the same bit rate, of course, you will decrease the signal bandwidth and the sound quality also.
You can decrease the bandwidth and loose sound quality if you do a conversion even to a higher bit rate.
And you can not increase the signal bandwidth using any linear transformation.

Well Spas you might be right to be honnest I didn't even read the whole post (too much info I don't need in my head) most of us we are not sound engineers so I'm with kinad here on this one but of course it is up to you and many thanks for all the great music you bring arround on our site