Never used anything other than bog-standard supermarket unleaded, or E10 as it's now known, in any car that I've owned and never had any problems whatsoever. If people are that bothered about keeping their engines/injectors clean they should convert to LPG as that's the cleanest fuel you'll get.
If you have a super-duper engine then yes, super-duper petrol makes sense. If, however, you have a standard engine that isn't tuned to use the super-duper petrol, then it's just a waste of money.