There is nothing wrong with JW Black. It's a nice, relatively inexpensive, scotch to enjoy at the end of a day with a cigar. Not too fancy, just pleasant to drink. I've tried all of the Johnnie Walker brands,(except the King George V Blue Label because it's $5,000.00 a bottle!) and I have to say the Gold label is hands-down my favorite. I've come into possession of two bottles recently, and I'm thinking about surprising a special lady with a bottle of gold when I go back to see her.
Back to the Gold Label, it's best served ice cold (near or at 32 degrees) with a tiny splash of water complemented by a dark chocolate (60% cocoa, or higher if your taste buds can handle it). The blue has more complexity, and is a superior scotch, but it is not anywhere worthy of the marginal value over the Gold Label. Gold will run you between $80-$100 a bottle. I think the Blue Label is around $250 or so. I'd say the Blue would be worth it at around $150.00 a bottle. It's just not worth the price I'm afraid.
Whew! That's probably more information than you care to read, but I hope it helps. In summation: buy the Gold Label, some dark chocolate, and never look back!