This is a touchy subject with some guys. They are the first to tell you about that situation their "bike I used to have" got me into a pretty sticky situation. They go on to describe a situation in which they were climbing a hill and didn't make it to the top. Usually the fault of the rider, not the bike. Truthfully, every bike is different. Now, I am not really the most qualified to speak on this subject because I have never really owned a 2 stroke motorcycle. That is unless you count the Yamaha 60 I inherited from my older brother. It only had first and second gear. The back tire was flat and we never bothered trying to get it fixed. Suffice it to say, I prefer 4 stroke bikes over 2 stroke machines. Why, you ask? Well, I was told by someone I trust that 4 stroke bikes are more reliable than 2 stroke. I have come to find out that this is not necessarily correct. Newer 2 stroke bikes are pretty reliable, and from what I have heard, they are hella fun. I will let you be the judge of that.
Some advantages of 2 stroke are simplicity, light weight, and power delivery. Two stroke engines are less complicated, so theoretically you can do your own maintenance on them. There is also a distinct sound that accompanies a 2 stroke. They can also be slightly cheaper to rebuild if you end up having to go that route.
Some advantages of 4 stroke engines are torque and predictable power delivery. You don't have to worry about "hitting the power band" with a 4 stroke. Hitting the power band is a saying describing a situation where a bike suddenly comes to life and delivers an unexpected burst of power which puts you on your ass. Another characteristic is reliability. I have found this to be true. As long as you properly maintain it, it will run season after season. A 4 stroke is likely to get better fuel economy than a 2 stroke as well.
The choice between 2 and 4 stroke ultimately depends on your priorities. Some folks prefer the power and sound that a 2 stroke delivers. Others prefer the versatility and ease of use that goes with a 4 stroke. It's entirely up to you. All I can say is that you will have fun with whichever type of enduro motorcycle you choose. Hopefully I see you out there some time!