Do you think that There is a difference between hovering a foamy and a 40% gasser?
Tell me what you think.

Yes, I think there is a little difference. The big difference would be cost and also nerves. I don't seem to care what happens to my foam airplanes but when it comes to my Hanger 9 33% Extra I stay up higher in the air and normally don't push the limits.

Bevo

Yes, there is definitely a difference. The biggest I can think of is mass and inertia of the airframe. The 40% is not going to be as "twitchy" as a foamy airplane....and a bit slower to respond to stick movements simply because it's a much larger plane. It also won't get knocked around in the air as much as a foamy.
Gas engines also have more of a throttle lag than electrics. With an electric motor....100% of the torque is available from 0 RPM up, and blipping the throttle results in instantaneous response from the motor. With any glow/gas plane, there will be a little bit of a lag from when the carb opens up to when the engine actually spools the prop up to make the airplane respond.
Others who understand aerodynamics better than I can probably share more differences.

assuming you mean foamis vs larger electrics... Actually the larger birds (80"+)are as easy as the foamies to 3D, even easier (just don´t tell anyone ) the hard part is in your head... lot´s of monay dangling 3" of the ground...

[link=http://www.henke.rchomepage.com/video/promotion1.wmv]3000watts flown foamiestyle[/link]

Huuuuuuge difference...

The Bigger the better

3D foam planes weight to thrust ratio along with large control surfaces make for an interesting combination of flying[8D]. Along with their light wing loading and flight characteristics and abilities to do most 3D manuvers with ease for a fraction of the cost of others..Doing risky and low manevers can be extremely costly but on the foam models a mishap can usually mean just a bit of glueing or a prop or gearbox shaft replacement..

There's times I'd risk a less costly plane than one that cost 10 times as much..The smallers planes can hone your flying skills that will transistion to larger planes as well..Defitnetly cause for the foamies and gas counterparts..

If noise-space restricts flying areas the foamies are a good solution..as some can be flown in a gym as well as outdoors.The foam plane can condition- enhance muscle memory and coordination for flying larger gas planes also..

Foamies are not meant for higher speed the gas planes are capable of, and there's nothing like a scale plane going through its paces..I like both..For perf. both deliver, but for cosmetic appeal the gas plane win on that one..I always find myself admiring a full fuse plane or a gasser with a smoke system..

Be hard to choose just one, as both have there places in this full-filling fun hobby..Fly both and excel

What he said. foamies are fun after you've put away the big toys and had a beer or two.

Mike