My 11 tear old iMac was starting to show its age, infact it has been for a while now. Slow loading, delayed and partial loading of Macmail - that sort of thing.
So I decided to try replacement of the HD with some of this new fangled SSD stuff. The difficulty was finding a local Mac specialist. As luck would have it I passed a newly open shop when I happened to be in Skunthorpe a few weeks ago that specialises in said Macs and whilst we were in Skipton couple of weeks ago [along with half the forum :) ] I left the iMac with them.
iMac (21.5-inch Mid 2011)
1TB Crucial SSD - £56.11
Data Transfer - £39.00
Labour Tier 1 - £49.00
Internal Cleaning - £0.00
Like a new machine ! Just waiting for some extra RAM to arrive now and we should be cooking.
My iMac is now 12 years old. The only thing I have ever done is add some more RAM a couple of years back which made a huge difference. The main problem now is that the software (High Sierra) is now no longer being updated and I am finding that it no longer compatible with some websites
You'll have to download a copy of Microsoft Edge / Chrome or Firefox to get around that one. Basically the in-built Safari uses outdated secure cyphers so won't be able to get to the majority of sites.
If Edge installs just use that. It's the best browser out there at the moment IMHO - and that's coming from a long time FF / Safari Mac user.