Was just gifted a few old iMacs, worth trying to upgrade?

[PeterB]

One 27" iMac, mid-2010 (iMac11,3), 3.2 Ghz core i3

Two 21.5" iMacs, late 2013 (iMac14,1), 2.7 Ghz core i5

Both in very good condition cosmetically and their screens are nice, especially the 27".

I presume the 2.7 Ghz will outperform the 3.2 Ghz?

Also, I assume not worth trying to upgrade the hard drives in these things, even though the SSD upgrade would most likely be the best thing to do?

The takeapart on these guys looks fairly horrendous... it's really a shame that Apple has made it so hard to upgrade anything.

TiA