I've signed up, because it will be worthwhile for me. I just need to amend shopping habits to two large shops a month, instead of a weekly largeish one. With 5 cats, I will save money on cat food alone!
I don't know where the £60 criteria comes from. At £7.99 a month, your two big shops need to clear £80 between them to start saving. In addition, there is always 10% of their own lines, such as Florence & Fred.
I've also got double data on my mobile phone.
Your existing club is still valid, I don't know how you got the information that it isn't.
I save my points up through the year and when it comes to a certain seasonal time, I swap them for vouchers at one of their named restaurants. This year I'm taking the extended family for a £420 blow out!