My new DSN snatched my autopen away in horror (& changed me to the solostar prefilled pen) because there is a known reliability issue. I noticed myself that the magic button you press to deliver the goods would either speed inject everything at once, or go REALLY slowly. Nurse tells me this means you get inaccurate doses and increases the risk of those gristley lumps on injection sites (for which I have completely forgotten the real name!).
I also learned an interesting new Lantus fact: the reason it hurts so much more than novorapid is that the suspension is slightly acidic. I suspect a sadistic chemist…