Advice on Staying with Win7 of going to Win8

Here is my SysInfo:
Tech Support Guy System Info Utility version 1.0.0.2
OS Version: Microsoft Windows 7 Home Premium, Service Pack 1, 64 bit
Processor: Intel(R) Core(TM) i7 CPU 870 @ 2.93GHz, Intel64 Family 6 Model 30 Stepping 5
Processor Count: 8
RAM: 6103 Mb
Graphics Card: ATI Radeon HD 5700 Series, 1024 Mb
Hard Drives: C: Total - 610377 MB, Free - 229670 MB; F: Total - 953866 MB, Free - 669390 MB; M: Total - 7 MB, Free - 2 MB; N: Total - 238409 MB, Free - 218514 MB; O: Total - 953618 MB, Free - 953498 MB;
Motherboard: MSI, H55M-E33(MS-7636)
Antivirus: Norton Internet Security, Updated and Enabled

My situation is that win7 is slow to boot and slow to run some apps, and now it will not recover from Sleep Mode but Hibernate is OK. I've been running on this PC for almost 2 years now and have not cleaned up and reinstalled win7. My thoughts are that if I need to go through all the hassle of reinstalling win7 from scratch and then installing all of the win upgrades and then apps, etc that it may be time to switch to win8.1.

Any other recommendations are sought after.

Kind Regards, Richard