advocate and advantage are pretty much on the same level for flea treatment
(read the info about advocate - it's basically advantage with an added worming ingredient)
but when using advocate, remember that it doesn't treat tapeworms. you'll need a separate product to treat for these.
i'll sing it's graces for lung worm coverage however.
also re: bob martin, don;t poo-poo all their products straight off, bob martin double action is the same as advantage (same strength, same active ingredient, same dosage, but probably a different carrier liquid) i recently picked up a three month supply for £8 at home bargains for my dog, where as a 4 month supply of advantage is around £12 for him.