Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
I’m running High Sierra on a mid 2009 MacBook with a 500GB HDD. It runs great for only 4GB of ram and being almost 10 years old.
 
Thanks much - upgrading now to EC and then to HS. What about switching to SSD?

SSD will greatly speed up your Mac and its a good idea.

Given that High Sierra has just been released it might be better idea to wait 2 or 3 updates before installing it. Keep in mind that High Sierra has mandatory new APFS filesystem if you install it on SSD. New filesystem may have issues so waiting may be better choice...
 
10.6.8 --> 10.9.5 --> 10.11.6 --> future stable macOS

My 2010 MBP came with 10.6.3 upgraded to 10.6.8 for stability... 10.11.6 is where I am now.

Waiting for 10.13 to stabilise, else it will remain 10.11.6 forever until I get a new machine...
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.