Another rookie question for ya. What is the differance between a bike that has a straight top bar and one that has a slopling a top bar. Like a Trek 5000 against a Specialized Tarmac comp. Is it just looks or is there a differance in the ride? Thanks

Nothing.

Marketing.

... Brad

Straight bar looks good, elegant, classic, sloping bar not so much. Also, straight bar makes it slightly easier to lean on the bike at the start and finish.

With a sloping top tube, the seat stays and seat tube are a bit shorter, so the frame weighs a tiny bit less than a flat top tube. Maybe the trend started so that manufacturers could claim they trimmed 50 grams off their frame. However, you'll need a longer, beefier seatpost, so it probably cancels out.
I like the classic flat top tube. Someone said Cannondale now has a sloping top tube bike !?!? If so, WRITE & COMPLAIN !!
+1 on the comment about leaning on your top tube before & after races !

I got a sloping top tube for my first bike. My next bike had a flat one. By comparison, bike with sloping top tubes look like they have Downs Syndrome.