Best Mac OS for these older Macs?

[DryRot]

I know a few people who updated their older (and eligible) Macs to Sierra and have had a lot of grief with their Macs slowing to a crawl and/or running hot.

I want to avoid that fate with several Macs I own or look after. Their OS’s are getting long in the tooth, so I would like to know what is the best later OS for each one.


#1 - Early 2009 iMac.

3.06 GHz Core 2 Duo. 8 GB RAM. 480 GB SSD (third party – Transcend), currently running Mavericks.


#2 – 2012 Mac Book Air

Maxxed out specs (whatever the best available chip was and 8 GB RAM), currently running Mountain Lion.


#3 – 2010 Mac Book (white plastic)

Core 2 Duo, 8 GB RAM, conventional (spinning) hard drive, currently running Mavericks.


I don't really live in the Apple ecosystem, so the latest bells and whistles (and emojis) hold no interest for me. My main concern is having relatively recent Safari and Firefox browsers.

Would appreciate your thoughts and experiences as to what is the best later Mac OS for each one.


Thanks in advance.

 

[keysofanxiety]

El Capitan or Sierra for the first two. Upgrade the 3rd with an SSD and update to 10.11/10.12 as well.

 

[Ebenezum]

Early 2009 isn't officially supported by Sierra. There are ways to install it if you want to but it might not work.

Firefox supports Mavericks so there is no rush.

If you decide to install El Capitan or Sierra test it first on 1 Mac, if you have problems its much less work to restore 1 Mac compared to 3...

 

[DryRot]

Thanks for the replies. Upgraded the MBA with El Capitan today, turned off Transparency and I'll see how it goes.