I would say the answer depends on YOU and what you like and are bothered by, not the places themselves.
Butlins will have a significant contingent of people smoking/vaping and drinking from mid-morning, plus talking loudly and sometimes using bad language. There is a large tattoo and over-weight count in the pool. It depends if this horrifies you or not whether you will enjoy a holiday there.
Some people clearly enter into all of the above - fine, it is their holiday and they should enjoy themselves as they choose. You might not enter into the above, but be able to tolerate it without it spoiling your holiday and recognise the good things about Butlins like the large pools, fairground rides, improved accommodation and good value (outside school hols mainly). However, if you're someone who will feel upset about seeing people vaping or behaving in a rather 'vulgar' manner at the evening disco, or will feel upset that your children see it, it's probably not for you.
The evenings I think are what set the 2 apart. Butlins has lots of evening entertainment - shows, discos, bars open. Not everyone goes but lots of people choose Butlins for the entertainment. Lots of people who go to CP don't want entertainment in the evening and shudder at the idea of early evening children's discos with a bit of agadoo or other action dances. Instead they want a meal at the lodge or perhaps in a restaurant,mfollowed by children in bed and then a nice glass of wine in the living room or outside - it's not about communal activity in the evening, or at all to be honest, although obviously lots of people are there most of the time.
Butlins is trying to be a bit more upmarket. If you look at the website you don't see people vaping or boozing but nice families enjoying an ice cream together. However, they know their market and still offer instalment plans to pay for the holiday with low deposits, cheap not-updated accommodation and entertainment which appeals to some groups, along with the more fancy and pricier newer accommodation and range of restaurants to attract those with money to spend.
In the end, you could have a great time at Butlins and do it for less cash IF you are aware there is a more mixed clientele and you aren't bothered about it. If you will be phased because you are either totally engulfed in a middle class bubble at home, that you've never seen how others like to spend their time, or if you're upwardly mobile and tend to look down on your roots a bit, it's probably not for you. But if you are able to take it for what it is and the people too, accepting there will be a wider range (and actually it might be quite good for children to see that too) you can have a great time.
Oh, and I don't think CP is quite as exclusive as some people imagine. Yes it might be pricey but I think you'll find there are quite a lot of non-middle class markers there too amongst the people. There are plenty of working class people with plenty of money to spend. But perhaps they aren't the markers which are quite so loud, so people aren't so bothered about them!