Ronald,
I have a mid 2013 13" MacBook Air, and I have successfully upgraded it from Mavericks to Yosemite, and last week upgraded from Yosemite to El Capitan. For El Capitan, I waited until OS 10.11.1 was released. For all of my upgrades/updates, I make sure that I am prepared. What I do is:
1. Wait until all the software I use is compatible with the new OS, or with the upgrade. If one only uses Apple software, that makes no difference. But I use quite a lot of third party software with both of my Macs, and some of them are very critical.
2. I keep my machines "lean and clean", via my weekly cleanup, Disk maintenance/repair, and backup routine.
3. I always have two bootable backups (made with the excellent product SuperDuper!) on two different external devices, for both of my Macs.
So far, OS 10.11.1 seems to be fine, and I am not having any issues whatsoever. If and when you decide to update/upgrade, make sure you have a backup first of your current system. Time Machine is fine, but it does not make a bootable backup. Having a bootable backup allows one to easily go back to their previous, working system.
The only remaining issue is whether you just want to upgrade from Yosemite (I assume that is what you are using) to El Capitan, or Erase, Format and Partition your internal drive, then do a clean installation of OS 10.11.1, and finally use Migration Assistant to "migrate"/copy all the non-Apple stuff from whatever backup you have. But, if I were you, I would strongly recommend using something like SuperDuper! to make a bootable backup of your current system.