Noel Edmonds is another awful sleb. Dealt with him twice, once when he was setting up one of his "Crinkly Bottom" theme parks and again with one of his "Garden Parties" day attraction. He was definitely an arrogant "don't you know how famous and important I am" type of person who could switch between his public "nice guy" image to his real self instantaneously.
By contrast, the kindest, nicest, most genuine sleb I've ever met was Olivia Newton John (RIP). I've never heard anyone say a bad thing about her. If anything she was nicer in real life than on screen! I met her in some public toilets in a shopping centre early 80s at the height of her fame/career. I came out of a cubicle and she was there, stood at the basin touching up her make up in the mirror. I looked at her and thought "no, can't be", she saw me staring at her and gave me a lovely smile, then turned around and started chatting. I was a tongue-tied shy teenager and was struck dumb. She started asking me questions to get me talking, i.e. what I'd bought, for what occasion, etc., and I dumbly nodded and answered as best I could. She told me where she was performing, what she'd been shopping for, etc. I asked for her autograph and then realised I didn't have paper nor a pen - she handed me her PA's card (Dana I think her name was) and told me to give her a ring or write to ask for a signed photo. Needless to say I wrote a nice letter the next day, but didn't have high hopes that she'd reply (I'd written to other pop/film icons of the time and didn't get replies). Within a week or two (it was to/from Los Angeles after all), I got a small packet in the post with a couple of signed posters, a small signed photo and a hand written personal letter from Livi herself saying it was nice to have met me, saying she'd hoped I'd enjoyed the party (which is what I'd told her I was shopping for) and telling me to contact Dana if I ever went to one of her concerts and she'd get me a pass to meet her backstage. Sadly, I never did go to a concert which is one of my lifelong regrets.