My daughter has been on the omnipod for 5 weeks, can't comment on other pumps but this has been a revelation. We researched all of the pumps and the omnipod seemed to be the best option for her - no tubing, automatic needle insertion, it's very small and you can swim in it. (She is only 11 and with school swimming, dancing classes, PE etc this seemed the best fit for her lifestyle.)
I will be honest, I worried if it really would stay attached especially when she goes swimming but having just returned from a two week holiday I can tell you that once the pod was stuck on, it stayed put for the full 3 days despite her swiming in the sea / playing in the sand.
The pod comes in a sealed pack together with a syringe, you inject insulin directy into the pod and then put it alongside the PDM, this then transmits data to the pod - once it clicks thats it, you stick the pod on, press insert neddle on the PDM and away you go, you only need the PDM near the pod if you are pumping for food you are about to eat.
Prior to us getting the pump I contacted Lee at Omnipod, our local rep and he sent us a sample so we could see it for real as it were and understand just what was involved, we then approached the hospital and requested this particular pump. (They hadn't used this particluar pump before but again Lee went into and trained the diabetic team and them we meet both him and the team twice over 2 weeks to get it set up.)
Getting the pod off also hasn't been a problem, I initally bought Appeel medical adhesive removal spray but have found hair conditioner works just as well.
It's still early days for us but no regrets so far.
Hope this helps