First of all: Welcome from Germany!
I have about 10 cookers, including a smoking pro (which I really love), a Louisiana pellet cooker and 2 kamado cookers.
And I also agree with drholly, that it's the cook and not the cooker - but never the less the cooker can make life much easier for the cook.
If you are limited to get just one cooker, take a kamado: I don't have a PBC, but I'm convinced, that it's an outrageous cooker and the folks here on LTBBQ are very enthusiastic on it. But as Sam3 already told it's a power cooker. So if you just want to take one cooker, it should rather be more universal.
A pellet grill is very easy to use and has a bright range of temeratures to work with. Depending on the product you are limited to indirect cooking, while Memphis and some other have the possibility for direct grilling. But be aware that, although they burn wood pellets, the smoke flavor is VERY decent: Most folks here use cold smoke generators to get smoke flavors to their food.
IMHO a kamado style cooker is most universal: It has at least the same temperature range like a pellet cooker (I think it's getting way hotter) and is almost as easy in use. The pro is, you get it very fast hot. The con is, it's VERY slow cooling down. But it keeps temperature very constant for a very long time. It's also very economical in use of charcoal. You light the charcoal and after your job is done you close all drafts to turn the fire off; next time you cook with the same charcoal. And it's very easy to smoke your food: just put in some chunks of wood or wood chips.
So you can use it for long jobs and smoking as well as a PBC style power cooker and as a high heat cooker for steaks and even pizza.
For indirect cooking you put in a plate setter, for direct grilling you take it out. In a Primo Oval XL you can even work with two temperature zones: one for direct grilling and one half covered with a plate setter for indirect cooking. For more space you get extended cooking grates.