I'm terrible about actually using symlin. Being on a pump, I find the vials highly annoying. I do plan to try it again this summer, while I'm not working so that I can be more cautious regarding lows. Next time around I will get the pens. Unit to unit it should be the same as using a syringe, just more convenient. Insulin is that way as well. I already carry backup pens of humalog and levemir in case of pump issues, so one more won't be that hard and I'll have the needle tips available.