I don't have a chrony, but it looks like the same trajectory when I shoot a 45# savannah and a 50# stick with the same arrow at 30 yards.  Anybody else experience something like this?  Quite an eye opener and something to consider when people ask questions such as "Is X number of #'s enough for deer or elk?"

It will vary some from bow to bow, but yes, you can get more speed from an R/D bow. My 46# Kanati will shoot faster than my son's 50# Martin Stick.

On the other hand, the D shaped bows will be quieter as a rule. There will always be trade-offs to consider.

Which one do you shoot better?

All depends on who made which bow and what they were made with. In general RD bows will be quicker.

Yah, it could be pretty close with light to medium arrows. With heavy hunting arrows the straight-limbed bow will hang closer as they are more about power than speed. My straight-limbed bows feel a little sweeter in my hands and are quieter. I usually score better on targets and 3D with my r/d but I take my D bows hunting. - lbg

speaking only of experience with light arrows, because that's all I can shoot now, I have consistently found that recurves are clearly faster than my D bows. Makes at least an 8 yd difference for me in terms of sticking with my known target image.   I haven't shot RD's as much, though I have some, but it makes sense to me that they'd fall between.   Any individual bow can break out of the pattern, of course.    all that said, I still love those longbows... and now that I have just begun the adventure of making laminated bows, it's old style longbows that I'm making

A R/D longbow will generally have more early draw weight or preload on the limbs. (more taunt string at brace) This will give more thrust at the end of the power stroke thus giving more speed.
Chad

noise and speed are related.
If you go to a higher performance bow, it allows you to add arrow weight. In the end you end up with the same speed to get the bow quiet but with a heavier arrow.
So ask yourself, do the game i hunt require a heavier arrow. 200# deer don't require much but a 1500-1800# moose have bigger ribs, legs, mass, width, and a pass though is always desireable for a good blood trail. If you hit a bone, will the arrow go through it and keep going.
IMHO you can never have too much killing power for the chance that you hit a front leg or scapula. When a deer jumps, it first crouches before bounding, that is why people miss over the top of the deer, it heard the shot or the arrow sound approach and instantly crouched to jump. Hunting is not target shooting. deer does not = elk. You need more punch for elk.

Generally speaking a R/D bow design stores energy more efficiently (more ft-lbs of energy stored per pound of draw weight, also known as SE/PDF) than a "D"-shaped bow.  Therefore it has more energy per pound of draw force to transfer to the arrow and that's why R/D bows generally out-perform D-shaped bows.  It would not be surprising at all to see a R/D bow 5 or 10 pounds lower in draw weight equal or even surpass the performance of the heavier D-shaped bow.  Bottom line: not all bow designs offer equal performance at equal draw weights.  All bows are definitely not created equal.

Maybe this tutorial will be useful:
http://acsbows.com/bowperformance.html

My 49# ACS CX, which is an R/D, keeps pace with the 60# D shape and 58# recurve I was shooting before. The same 600 gr arrows were flying at the same speed out of all three bows.

Black swan makes a D-shape that will perform with most hybrids and recurves.  It just depends on the bow.

My 45# tomahawk r/d longbow was chronoed at 3fps faster than my 50# D longbow.