The notion that OS X 10.7 and greater "have become iOS" is completely over-stated.
You might wanna watch again Apple Special Event October 2010 themed "Back To The Mac"...
Yes, there are gestures, like on a touch screen. But also like on a trackpad.
You have not lost any functionality: you can still use keyboards and mice.
This is the only one feature I appreciate post-SL. However BetterTouchTool can simulate these touch gestures on SL.
Piece of crap. I would love Apple to remove this feature if lesser processes and APIs related to LaunchPad could improve overall UI performance.
Half-baked service. I've got nightmares dealing with iCloud at an early stage that duplicated all of my data on my Mac and iPhone. Just recently I made a mistake of deleting all my Notes (mostly sermon notes) on my Mac sync to the iCloud, hence they all vanished on my iPhone as well. Thankfully I had a backup on my iTunes which I was able to restore about 80% of my notes.
This is the downside of syncing to iCloud as opposed to iTunes. If you happened to delete some stuff on your iDevice, the deletion process goes all the way to iCloud and the rest of your connected devices, there's no turning back. With iTunes, however, you can still restore from backup. Sadly on Mavericks, the Info tab on iTunes is missing, so there goes syncing non-media contents of your iDevices from your Mac.
It's a good thing Apple did not include iCloud on a supposedly 10.6.9 update, otherwise it would most probably be slow and buggy as Lion and beyond.
Yes, iSync no longer works on Mavericks though they still work on Lion and Mountain Lion albeit hijacking a copy from SL. I still have an old Nokia E71 of which I sync my contacts onto.
CUDA is almost useless on Lion and Mountain Lion due to some VRAM leakage. Total lost on CUDA capabilities on Mavericks DP4.
No. Has the UI been "dumbed down"?
Yes, ever since Lion (with it's choppy GUI), and some things done with a single gesture is now twice as much to accomplish certain tasks. Take for instance I want to use iCloud on certain apps like Day One for OS X (and for some odd reason Mavericks had some bugs related to loading existing libraries especially on cloud-based services like DropBox that forces me to use iCloud), I have to switch on "Documents & Data" sync. For this, every app that is iCloud-enabled, say TextEdit and Pages, now I have to decide where to save a file even before I start my work on it.
So has it "dumbed down" the UI...? A very strong YES...!
1. AirDrop seems useful, but it's awfully slow, and I only have one Mac to deal with.
2. iMessage is pretty handy, but with the frequent service disruptions, it's slow and unreliable. From where I am, Whatsapp seems to reign, sadly they do not have an OS X version.
🙁
So in short, NO...
Do you still have a phenomenally powerful general purpose device, whose capabilities you are probably using only a fraction of? Yes.
The former, yes. The latter, I do much more than that. That's the reason why I do not have an iPad. A MBP + iPhone (with iTunes) will do fine in simplicity thank you.