Hi Frank
IMHO really not worth the effort unless you are interested in tat and faded tat at that. I last went as a child and at that point swore I would never go back and over fifty years on, still haven’t. So my opinion might well be out of date, although I suspect it isn’t. I know some folk enjoy the attractions of Blackpool, but it has never been of appeal to me.
My best argument is if you are so close to the Lake District, why bother with Blackpool? If you had planned on the Lake District anyway, spend more time there instead! I know to some people the Lakes are only Windermere, Bowness and Ambleside, but while better than Blackpool, they are still very much tourist central. For a more rural experience I’d aim for Coniston, Wasdale, Buttermere and at a pinch, Ullswater. I’ve not made it to the Isle of Man yet, so cannot comment sagely, but my friends, (whose opinion I trust) who went recently said it was interesting, although a mix of the very nice and well kept with areas that have seen better days and need improvement.
Have a great time, wherever you go!
Ian