I disliked the Speccy back then: I owned a C64 and my friend a Sinclair (which was a Spectrum clone if I remember correctly) and back then I thought the C64 was so much better: better sound, better colors, less "artifacts" in color graphics...
... now I see the Spectrum and I have a newfound respect for it. It was technically inferior but there was a certain grace in how game devs worked around its limitations and weird color palette. And the graphics were crisper than I remembered.
Sinclair Research (after sir Clive Sinclair, the founder) was the developer and original owner of Spectrum. The classic Spectrum models are either from Sinclair or a version developed by Timex (who also did a lot of the Spectrum manufacturing, I think) under license.
There were a number of clones too, but Sinclair is the real deal and Timex Sinclair was officially licensed.
Later the Spectrum was sold to Amstrad - at which point you got the Spectrum models that looks like Amstrad computers.
it's strange for me now, looking back and appreciating the Commodore 64 for what it was - the colours that I thought muddy and awful as a child now seem considered and more broadly useful, the capabilities of the SID chip blowing away what the Spectrum was capable of.
And then there was the Amstrad - I simply can't recall its graphics being as good and as colourful as they clearly were. Blinkered fanchild shades, I guess!