Thanks for the comparison pics. I agree with icoopernicus that "rip-off" is a bit harsh given all the common designs there are between brands, but it's definitely a strong resemblance. Add some pictures of the Hamilton Jazzmaster, and you get triplets.
Re: the OP: I love old Heuers, but I like TAG-Heuer a lot, too. Before I was even "into watches", my dream watch was a Cal. 36 TAG Monza. Would still love to own one. I think part of of the reason why TAG gets a bad rap is because 1) they were so ubiquitous in the late 80s and early 90s as THE watch to have, 2) as cromag said, designs like the S/el did not age gracefully and 3) the constant advertising got obnoxious (Senna, yes. Leo "I can't be bothered to actually wear this watch" di Caprio, no thanks.).
And I have to say, I like the direction that TAG's headed these days. I can't say the same for old favorites like Omega and Rolex.