I've used the patches for quite a while, and they really help. I like the 24/7 coverage, and most brands will last the full 72 hours. Watson pharmaceuticals began selling a generic patch this year, and theirs are terrible. They dispense too quickly and the last 12 hours are just h**l. For me, the patches made by Mylan are the best.
Most people eventually have issues with patches staying on the full 3 days. If you have very oily skin, you'll have issues with that. I use a tegaderm cover over mine that is made by Nexcare, and it works really well unless I stay in the pool too long or sweat a great deal. Some people notice they get woozy if they run a high fever or are out in the heat. Higher body heat can cause the patch to dispense more quickly, which causes those symptoms. I've only had that happen twice in 3 years. I've had the best results keeping the patches in place by putting them anywhere on my ribcage. I've tried using my arms, but I tend to scratch them off in my sleep that way. You just have to experiment and see what works.
While fentayl is a great deal stronger than morphine, you can't look at it that way like you're taking the top of the heap medication. To show you how strong it is, other opiates are measure in milligrams but fentanyl is measure in MICROgrams. I went from 6 norco a day (one norco containing 10 mg hydrocodone) to a 25 mcg fentanyl patch and didn't really notice any change other than better pain management. I didn't get high, or goofy (well, goofier anyway) or fall asleep drooling on my chest. Hopefully that gives you a better basis for comparison.