Been using Mavericks since day 1, upgraded from Lion (skipped Mountain Lion).
It’s been running great on my 2009 Mac Mini and GF’s 2012 MacBook Pro.
There is a known problem with HP Scanners, the HP software doesn’t work but you can scan with Preview
Some Western Digital external hard drives running their software have a problem with data loss, that’s due to the Western Digital Software not being compatible.
You might like to have a look round the excellent Mac Rumors forums for the issues you mention.
Having been using computers for 30 years I try and avoid anything Microsoft if I can, when they bought Skype for me that’s a negative. I still use it but only on my iPhone or iPad (so iOS not Mavericks), using FaceTime more and more.
@seosamh77 – screen mirroring to Apple TV (large HD TV now an additional monitor if/when required – using that right now, memory management better, macbook battery life better, new safari with notification centre and power save features, finder with multiple tabs and tagging, free upgrades to pages and numbers (I rarely use Microsoft Office even for work), new KeyChain over iCloud, general iCloud improvements and connectivity.