has changed in the last few years. Consumer camcorders are still saddled with AVCHD compression, low compression camcorders appear only in prosumer and above.
The Canon HF-M301 has a 37mm lens filter diameter and 1/4 inch single imaging chip.
The JVC GC-PX100 has a 58mm lens diameter with a 1/2.3" single imaging chip. This is quite robust for consumer grade. I guess I'd like to understand how you are viewing the video from the different camcorders where you are not able to see any major differences - or what their video quality capture settings were...
The upside is that some of the higher-end consumer cams (like the Canon HF G20 and I suspect your PX100), while using AVCHD compression are able to apply a lot less compression. This should help a little, but the whole AVCHD 8-frame group that defines the AVCHD compression algorithm is not in your corner with fast action.
In your case, since you can't make the lighting better, you may be able to get away with the larger lens diameter and imaging chip (though you say you did not notice any difference). This might allow you to slightly increase the shutter speed to where you want it even under the lighting you are encountering - it will also be helpful to use the white balance settings (rather than "auto").
Video capture is not getting a bunch of still images and putting them together like a flip book. And where there is motion, there will be single frame blurring. That is not how video is watched... Video is motion. If your goal is to capture awesome video that can be used for amazing slow motion or still image capture like you see on TV when the TV stations broadcast, I can assure you they are not using a consumer handheld camcorder... Those cameras start at about $80,000 and go up - then get the lenses added (and they don't record locally, but feed into a control room or truck for storage/switching/graphics and audio is handled separately).
The last high school basketball game I did was a couple of years ago. The most useful video I got was from a tripod-mounted Sony HDR-FX1 (replaced by the HDR-FX1000). Shutter was set to 1/250, I think... I was on the floor, not the stands (so no vibration from folks walking on the bleachers). The lens diameter on these is 72mm with a 3CMOS 1/3" imaging chip array. The low compression and non frame-group compression is more useful for fast action. I through some slow motion in during editing (it is much better and more technically challenging to capture at a high frame rate and play it back at normal 30 frames per second). Capturing at 30 frames per second and slowing to about 15 frames per second worked fine. The 1/250 second shutter speed worked well, too - any faster and on playback you can get an odd strobing effect that is not fun to watch for long periods.
I would expect the daytime games (sunlight) to look pretty good with either the Canon or JVC you used. The indoor lighting for basketball or night-light outdoors could pose issues.
Another item on using a dSLR - check the manual. Normally, there is a note on the dSLR overheating (after about 20 minutes and automatically shutting down until cooled (about 10 minutes). There is also a note on the sequence length limited to 29 minutes and 59 seconds...