If you look for opinions here, of course you will only see negative reviews. This is a support forum.
1. A OS X upgrade doesn't delete anything, but you must make a backup before upgrading with Time Machine and/or Carbon Copy Cloner. If the upgrade fails and you haven't made a backup, you will lose everything.
2. If you are upgrading from OS X Lion (OS X 10.7.5 is Mac OS X Lion), most of the apps will continue working. Anyway, you should check if your applications are compatible > http://www.roaringapps.com
3. That's the upgrading myth. In my case, I haven't experienced any slow down just because of upgrading Mac OS X, but in some cases, you may notice it. Normally, it's caused because of an unsupported app or a defective upgrade.
4. Can you explain this question?
Look for every point there is negative as well positive point.The same is with lion as well.
Look Im also on mountain lion(10.8.2)>and its very awesome and for this there several more games which 10.7. series doesnt support.
Look there is a chance of getting files deleted.So all you can do is take a backup of your data before upgrading.
Its very fast while its on.
It takes little more time in turning on as compared to 10.7, but once its on its more fast then it.
Or I will suggest is you first try the demo on apple store.In that way It will be more exact you to compare with yours..
Are any of my files going to get messed up/deleted?
Not if the upgrade goes smoothly, if it doesn't due to a unknow glitch, then yes, your entire Macintosh HD partition may require erasing to fix the issue, which will also erase your files.
So you need to backup personal data off the machine before inflicting any sort of major change.
Will games/apps not work anymore?
Programs using PowerPC processor binaries old older Mac software will not run on 10.7 or 10.8 anymore, however will do so under 10.6 using the supplied Rosetta that gets installed automatically.
Some apps/games are not updated or tweaked for newer operating systems as it will cost a lot of money to do so.
Some apps will require a paid upgrade.
Will upgrading slow down my computer?
10.8 and 10.7 (and 10.5) are slower than 10.6 freshly installed on the same hardware, so yes, upgrading to 10.8 will slow your machine's performance down, less so if it's freshly installed (no other data on the hard drive.)
10.8 was designed for newer faster hardware with more features, it thus runs slower on older hardware, even slower on less powerful older hardware.
If your machine is older than 3 years and running 10.5, I say go to 10.6 and stay there.
If your running 10.6 on a machine less than two years old, then your a good candidate for 10.8.
If your running 10.7 already, then 10.8 isn't going to make too much of a difference.
have the MacBook Pro silver 2008 model and had upgraded it to Lion 10.8. As I had upgraded to a new iMac I gave the Laptop to my wife. I had transferred via Migration assistant from her Dell running Windows Vista. Unfortunately, I messed up the user accounts due to the way in which MiG Asst suggested I had two similar names, which then caused issues with filling my 250GB hard drive. In deleting User accts and other attempts to reclaim disk space, as I was faced with problems, I backed up to external drive. Then reformatted laptop and put back the Original operation OS X disks. Unfortunately I had overlooked these were V10.5.8!
I tried to use Migration Assistant via the external backup drive, but again worried about the warning about two similar User names. I understand that my latest Lion 10.8 is on the drive, but not confident how to recover it!
Basically I want to put the Laptop back to its former state as a simple laptop for my 70 Yr old wife to understand and use with her iPad. All her original files etc are still on the Dell Vista Laptop.
Any help would be so appreciated...