Well I broke open my eztest bottle and dripped a drip onto my scraping. Pill 1 checked out, so I did scrapings for pills 2-5 and just shook residue out of the eztest bottle and was able to test all 5.
I personally like the ampule, for all the reasons Sam has just mentioned.
Its also very safe and hygenic.
I have read once or twice on PR about the safety of them in terms of people cutting themsleves but ive had practice on several occasions and I can honestly say not once have I considered them to be dangerous to use.