I'm ok with Alesha, she's getting an undue hard time. For the most part, her comments are actually no different from the other judges; in the sense that sometimes they make constructive comments regarding the technicalities, and sometimes they say things that really don't have much bearing on the dance and are purely for the sake of 'entertainment'. I think she is doing a respectable job considering the circumstances. Be honest, if the BBC paid you a load of money to do it, and doing it would help boost other parts of your career, you would?
Do I think ageism regarding Arlene was a factor in why she was booted? Yes. Do I agree with it? Heck no! Fact is though, Alesha is not the one to be gunning for. Complain to the bright spark at the BBC who had been watching too much Xfactor and thought it would be a great idea to copy the format of young, overly glamorous, under qualified pretty things to make critic of stuff they have no in depth understanding of – at least Alesha is a talented dancer! Unlike her contemporaries on ITV who, at best, are mediocre at what they do.
But, you know, the judges are just talking heads – do they help you make up your mind about who is your favourite dancer? Probably not. Do they help the British public choose who they are going to vote for? I doubt it. Do you really think the professional dancers pay that much attention to the judges? Probably not, because Strictly is not a traditional dance competition. They are there for entertainment purposes only, it's a pantomime.
Seriously, if you don't like Alesha being there, please write to the BBC and complain about Arlene being axed because she is not a young, glamorous thing; because THAT is the real problem. The BBC was trying to pander to a particular youth orientated, Heat reading demographic, and in the process showed ageism, sexism and complete ignorance and disregard for its audience and own credibility – they were more concerned about getting someone who looked right than someone who was qualified and experienced. Though, of course, none of the old men got the boot, just the old woman, and I personally find that a more important issue than whether Alesha should be replaced. So please, do complain about that to the BBC.
I also notice she is getting a lot of stick for her grammar. People forget that they way she speaks is her local cultural dialect – there are hundreds, if not thousands of local cultural dialects across the UK.
To answer your question, clearly, if you had to pick one of the two, Karen would be a more appropriate choice. Though, as I say, I think Alesha is doing an OK job.