I have a Novopen 3 for my NovoRapid and an OptiClik for the Lantus. The Novopen is quick, simple, easy to use, robust, and has, as @lizz says, a good feel to its metal body, it’s a great piece of kit. The OptiClik is cheap plastic, and although it has a digital display, the mechanism is ‘fuzzy’ rather than the positive dial up of the analogue Novopen. It’s not nice to actually get the needle in and find out you can’t press the button as it’s a micro-metre out of place!
The Novopen is so good, I’m seriously considering changing my Lantus for the Novo Nordsk equivalent (Levemir I believe). As my hands become increasingly arthritic, I may well find it difficult to apply the much higher pressure required to use the OptiClik, whose only redeeming feature is that you can dial up 80 units, rather than the Novopen’s 60. On the other hand, the Novopen is so easy, you can dial up an additional dose without removing the needle from your body. Now that’s got to be good! 