I've for some reason got into the habit of not using the clutch when downshifting while breaking hard. Got into that habit riding 2 stroke dirt bikes and always wanting to hear (more like feel) that I was in powerband.

Find myself doing that now on the Preddy. I don't think it would hurt anything, but probably not the best of habits.

 

I used to shift w/o clutch...now that I blew my 3rd gear out, I will quit. $500 to fix!! The only people who should shift w/o clutch in whatever conditions they like are professionals who have paid mechanics so they can fix when something goes wrong. this will wear your gearbox down over time. Better feel, quicker whatever, that's fine, and all true, but when it comes to "breaking" something, you will eventually by not using the clutch.
My dad has smoked for 25 years and no cancer, so does that make it ok?

 

If Im play riding I always use the clutch. When racing, I will upshift without the clutch a lot, but usually use it to down shift.

 

its called slipping the clutch, this is how you do it! Give er' **** with the throttle and at the same time put a little upwards pressure on the shifter, when you let off the throttle the slightest bit, it'll up shift almost by itself!

Now only do this when upshifting, and never ever do it if you run automotive engine oil, becasue car oil has anti friction agents in it, which means it's trying to make your clutch discs slip when what you want is for them to stick together

 

Yea, don't use the clutch-you lose power. Just left off the gas so the engine is not under load and shift. Definitely go with the DVX 400. I know it is the same as the Z400 but it looks way cooler. Since you are already 15 you would quickly outgrow and be bored with a 250. My first quad was a banshee-prior to that I had never ridden and quickly grew unsatisfied with the stock power. DVX is a hot looking quad, reliable, handles well, and jumps well. Once you get a little faster you can add an aftermarket pipe and it will move.