ok this is general feedback to the osx development team.
as a mac person who has been using macs ever since an apple IIe , I think you need to understand that I consider lion and mountain to be a terrible upgrade : snow leopard irritated me but at least in functioned reasonably well.
the reasons :
I support about 50 machines currently the majority still pre intel cpu i series ie core series intel and most of my clients as users of mobileme felt obliged to upgrade to lion from snow leopard to continue using syncing in icloud.
of the machines I upgraded recently 3 intel core 2 duo based 24″ imacs with 4gb of ram all have become highly unstable erratic and have needed several clean reinstalls and are still highly unreliable doggishly slow and crashing. when the machines were perfectly fine under snow leopard ? one has now effectively become useless.
The quality of lion (im too burnt by lion to consider upgrading to mountain lion) whilst running on core 2 duo machines is unacceptable, I have so many issues i can barely keep track of them all. my support calls have multiplied by a factor of 5 since lion, not what i wanted form it. I hope in your testing you did many upgrade installs on core 2 duo based machines As i cant beleive the number of problems im having.
Mac os X mail has become unworkable, I suggest Mail needs a complete re-write from the ground up, and that mail should not be creating so many files in the way that it stores emails, for instance I have a macbook air whose mail folder is 30gb in size, I doubt the user has more than 5000 emails yet somehow when finder is slowly backing up his mail folder to a time capsule it claims its copying over 300,000 files, one can also see in mails operation all the endless tiny reads and writes it does to the disk anytime anything is done, this is inefficent, I suggest that you store an email as a single file and not as mutliple on the disk or maybe even entire threads as a single file, maybe linking attachments externally, whichever way mail seems incapable of handling the volume of email the averagee business user is now generating, just like how iphoto got rewritten to handle allot more images without bogging down, make it so mail can handle 10 email accounts 5 exchange/imap and 5 pop accounts and 100,000 emails in total in realtime then it would be upto the toughest users workload, as currently mail seems to crumble at 10,000 emails.
apples builtin applications and uninstalling and reinstalling them.
return to an age when all apps including apple apps can be uninstalled and reinstalled including all their subsiduary system files, and all their permissions corrected both user and system if need upon reinstall from a simple installer, uninstalling and reinstalling safari now appears to involve reinstalling the entire os ? not good for example I spent 2 hours trying to repair a safari install that wouldnt launch, on one machine, from a support perspective you cant justify spending such time on one os installed app otherwise it effectively means the app has now cost lots of money, this was caused by the fact that safari can no longer be removed ? and its cancer seems to have spread deeply into the OS as well, why did you leap on the attack microsoft over the os embedded browser war when you yourselves now appear to be doing the same ? the only way i could refresh the safari install was to reinstall the entire os ! this is rubbish and you know it. sorting a broken app issue should be as simple as uninstall app which also removes its system related bits then reinstall fresh app, in this case safari in total this process should take 5 minutes tops ? what is difficult to understand in this model ? its the only one that can work from a paid support perspective ? imagine your os from the perspective that all the support work is paid for at a certain rate per hour and that all fixes need to be fast and efficient. for instance another problem a mail backup to a time capsule directly connected to a macbook air with an 128gb SSD drive > total copy time for a 30gb email folder ?> 13 hours ?
storage in computers is the greatest slow down im finding at the moment you need to make a 10 fold increase in speed of storage used in all macs all mechanical drives as standard need to be partial ssd backed 7200rpm drives at least, just like momentus XT’s etc and then have an additional dedicated SSD boot drive as standard, and make this internal storage externally accessible and replaceable, you make my life as a tech support 4 x time harder than it needs to be.
Permissions and collaborative work between more than one user :
collaborative work on os x is weak, because permissions in osx are a nightmare, posix and acl permissions as used in os x are not functioning well and umasks arent either.
re-examine which of the core parts of os x needs re-writing as performance is currently weak.
It’s looking like some bits of osx arent being touched for fear of screwing them up, as in the person who wrote the code is long gone. maybe start the process of writing a new operating system from scratch not based on osx ? go back and have a look at the genius of mac os 7 , 8 , 9 which seemed far superior in many respects full gui control of the OS extensions etc, as soon as stuff goes pear shape in osx it seems terminal is the only solution ? this is a failing of GUI design.
remember you can consider every extra additional unecessary click made by a user may end up being be multiplied by every user, all of a sudden theirs trillions of clicks of worth of decision time is being unecessarily spent every year by bad design.
Give me control of these design decisions and I can make a difference. I better stop here I could give a thirty thousand word lecture on all the things that aggravate me about os x and macs in general, if you ever need consultancy as to all the stuff your getting wrong email me, pay my flight and ill come and sort you all out.