I've owned various scooters (150cc chinese POS, 400c Burgman) and various bikes (750 shadow, 250 ninja, cbr250).
I think what matters more is using the weight designated in the owner's manual, and changing it according to interval.
Here's why I say this...
The burgman ran 15w40. I put Rotella 1540 into it. The scooter & bikes recommended 10w40, or a slight variation of weight based on temp or riding conditions. None of them got very anal about diesel vs. car vs. motorcycle. Most said any vehicle (read as "automobile / motorcycle") oil would work.
Why? Because these vehicles are designed to be low maintenance. Nobody wants to pop tons of money on an oil change on a motorcycle. So, engineer/manufacturer designed them to just use off-the-shelf motor oils you can find at any auto store around the corner. It's cheap, convenient, etc.
Folks split hairs over type of oil (synth vs. dino/mineral), auto vs. motorcycle vs. diesel, and other BS. If they love to do that, that's great. That's their thing. But, bottomline, if you're just using your motorcycle and want to run it, just get a motor oil within the designated weight of your owner's manual. The manufacturer will almost always recommend their specific brand (eg: Honda always recommends their specific, more-expensive Honda brand of oil), but they state in the manual any oil falling in the weight range they give is acceptable.
If you're looking to magically eek out performance based on the type of oil you use, then you're splitting such a fine hair on a head full of hair it's not even funny.
As for oil changes, newer bikes (post-2000) can get away with greater intervals between changes. Cars and bikes in the past needed a change every 3-4k. But, if you look at car owner manuals most cars can go a good 10k+ between changes. Bikes are the same. Used to need a change every 2-3k, but now you can go 6k+. My shadow 750 could go 8k between changes. Same with the cbr250.
If you want to change the oil sooner, so be it. But, the biggest thing is to at least run the oil 1k+ or so. This lets the oil break in and run effectively. You could change your oil every 500 miles if you want, but you'd be wasting your money and not running the oil in it's optimial time frame (1k+ miles).
The biggest thign you can do for your motorcycle is just
1) use the oil within the weight the manual recommends
2) change it per your manual's interval (or maybe before then... some folks change it at 1/2 the interval their manual recommends).
The biggest consideration in oil changing is how much stress is on the bike. When I ran my little 150cc scooter I changed it every 2000 miles even though it said 4000 miles. Why? Because I'm a fat guy, and it hauling me around was putting a lot of strain on the motor. For the 750 Shadow, which is designed for hauling a fat-*** and/or two-upping, it could haul me around without breaking a sweat. I changed it every 8000 miles.
Bottomline, changing the oil is better than not changing the oil, and using motor oil is better than tossing cooking oil into it. Just ride it, have fun, and don't sweat the small stuff. If you really want more performance, then sweat over upgrading to a bigger bike, not over the type of oil you put in your current one.