I changed from Nove mix 30 to levemir and novo rapid about 6 years ago then to lantus and novo rapid and now to huamlin I and novo rapid. Like any time changing insulin it will take a bit of getting use to and fine tuning until you can get it right.You will get highs and hypos of course. It is good in the way that, if you are carb counting, it gives more flexability. You can basically eat what you want when you want and adjust or administer insulin when needed. You may ask why my bolus, fast acting, insulin has stayed the same throughout and and my basel, long acting, has change a few times. The reason for this is that although the basel is called a 24 hour insulin different makes behave in different ways some last maybe 20 hours some maybe 26 for example. This is where fine tuning comes in and you and your nurses/doctor will work out what works best for you. I was on one injuction of levemir when i first started and the same with the lantus. Until i was put on the humali I and i was switched to twice a day injections, 12 hours apart, and with more fine tuning it was found that i didnt need the morning injection. Like i said it will be taloired to you there is not one set way of using a MDI (Multi Daily Injection) regime for everyone. Just keep at it and it will work with time.