There's a much higher chance of contamination with the two needle method of drawing and injecting, though it is probably negligible if you use clean technique. I can draw up 0.25 mL (my current dose) in less than a minute with a 28G needle. I occasionally use a 30G and it's not a lot longer, maybe 2 minutes at the very most. Given the simplicity of the one needle method, I much prefer it, but everyone has their preferences. My motto with TRT, is that if it's not broken, don't much with trying to fix it. I tell my doc that every year when she suggests I try the gel.