TravelinColour is Chichester - I've not been to one of her days as she's too far away for me, but I know her through MN and she's been brilliant in giving me lots of advice in how to make my diagnoses work for me - which ime is the most important part.
It does not matter if the consultant is a different season/style from you - mine wasn't but she was spot on with my season and more importantly she made sure I could "see" my colours. That way you come away confident that you will be able to choose your colours when shopping.
HOC system is more of a science - they have been trained to diagnose your season and which of the colours in your season look best on you. If you go as part of a group, its worth watching the others as you will then be able to see how each colour change the way they look.
My consultant was about 20 years younger than me, and completely different from me in every conceivable way - and she changed my life, seriously!
I can't tell you how much more I enjoy shopping (and getting dressed) now. And I look 'finished' every single day. AND I've saved loads of money because I'm not forever buying unsuitable stuff and flogging it for a loss on ebay.