has anyone have any experience with it? i have one and i cant seem to get it to function correctly. anyone have any tips?

What issues are you having?

They have a history of being problematic, which is why my shop stopped selling them.

the only problem ive had is that it says im going 0kph right after i hit ~38kph after a year. i reset it and now it works fine. i say if you can get it at a good price then go for it.
i got a colour i didnt want for less than $40

I got mine for free and I stopped using it because it kept giving me problems.

Same here... I put one on my wife's tri training bike and the thing worked well for about two rides and then started acting crazy... Cutting out for no reason, etc. I even doubted myself and took it to my LBS shop and their mounting didnt do the trick... I really wanted to like that thing....

This was exactly what I dealt with with my first unit.
But Knog fully & gladly backs up it's product, hassle - free. Not to mention they gave me a cake of knog stickers.
Even though I still have mine, it sits gathering dust in a drawer, a fitting punishment. There's better alternatives for the price. Check out cateye's offerings.

Mines collects dust, but for the most part I haven't had much trouble with it.

meaning it collects dust very well?

take it as you will.

i got it to finally work. i hope it'll last me awhile.