I like Sixties/Northern/uptempo sounds & deep soul / ballads. Not really heard too many people refer to themselves as 'true Real Soul fans' in fairness, but I know what you mean.
Anyone who likes the former, but not the latter is a rare beast first and foremost. They are not seeing all the colours of the spectrum. If however they did only like the former, bearing in mind the amount thats out there, that I think would be soul a plenty.
To much dodgy modern disco, that's the thing to steer clear of.