I'm agreeing with Razor twice here. Even though I am relatively new on this site, I am now on my 7th or 8th batch of base, and I have to say, it tastes so much better in the finished curry fresh, rather than frozen.
Also, my first curry was a dhansak, in Manchester in the late 70's. It was unbelievably tasty. I used to cylce 5 miles on a Sunday night in all weathers after the pubs had closed to get a takeaway....it was worth it.
It was a very mild curry, a lot of lentils and chunks of pineapple. So, yes, there obviously are regional differences.
Mind you last time we visited UK (2009) we had a few curries in various Manchester restaurants, but by far the best curry we had was in Twickenham the night before we flew back out to OZ. Can't rememeber the restaurant name, my nephew and his wife took us there, but we ordered 6 or 7 different dishes, and it was SUPERB!!