Q: Upgrade to a later OS, Good idea or not ? Opinions please.

I have a 2013 Macbook Pro, 4GB memory and running the original install of Mountain Lion 10.8.5 . It is basically used for recreational use at home, no heavy graphics or complex word processing, stores family pics, use ebay, hobby forums, household running costs and basic banking etc. Nothing fancy or elaborate.

I am quite happy with Mountain Lion as the OS but am aware that it will gradually become obsolete and no longer supported by apple updates.

I am considering upgrading to Yosemite rather than el capitain as yosemite should now be bug/glitch free.

I was wondering if this sounds sensible and what opinions of those experienced users are ?

Am I likely to encounter any issues ?

Thanks

Brian.