TRex is always like that -- calling direct works. But the Disney restaurants, don't count on it...for starters, unless you happen to know the "direct" number you'll typically get a regular Disney dining rep who will tell you there's no availability. And I really wouldn't count on getting a walk-up between 6 & 8 p.m.-that's Prime-dinner-time at Disney so the most busy restaurant times.
Try 5 or 5:30 and you maybe have a shot at it but by 6:00 p.m., most popular restaurants have a long line of people waiting to be seated who all have reservations - you'll be behind them. We were at Kona Cafe on the Saturday before Memorial weekend, so not into the busy summer season yet at all. But at 7:10 when we were in line to check-in they were telling people with no reservations it would be 90 minutes until they'd be seated (small parties -- 3 or 4 people).
However, the restaurants do not fully book the very early slots so that they can gradually fill tables (obviously the can't seat 200 tables all at once -- would be a nightmare to get all the diff. orders ready in reasonable time. So they stagger the seatings until around 5:45 all tables are filled....and since they staggered the seating, the times people leave are staggered too...which keeps the flow steady all evening for wait staff/bussers/dishwashers/cooks)
Anyway, sometimes they'll take a couple of extra tables' worth at those early meal times if they have enough staff on hand to cover the tables and the cooking. But keep in mind just because the restaurant is empty when you ask doesn't mean they can take you...could be they just barely have enough staff on the early slot to handle the reserved tables...some restaurants stagger the employees start times too so they may only have partial staff on hand right when the place opens.
There are a lot of good restaurants, though...you mention Cape May Cafe. If that's for a dinner & you want the Epcot resort area...try Captain's Grill at the Yacht Club right next door. Not a buffet, but good steaks/chicken/seafood choices, and generally not as packed as Cape May. An alternative to Kona Cafe, but also on the monorail...either The Wave at the Contemporary or The Grand Floridian Cafe at the Grand Flor...again, both places have good steaks/chicken/seafood choices. Wolfgang Puck Cafe...have only been there for a late lunch on a Sunday and it was empty. Have no idea how dinner is. But a really tasty alternative in the near vicinity is Raglan Road (in DTD) or The Turf Club over at Saratoga Springs (either a walk from the Marketplace, or a boat ride from the Westside at Downtown Disney) Raglan Road has great entertainment (Irish band/dancer) if you're there around 8 p.m.
