I have had mine for a few months now, also my first ceramic. I come from drums, WSM, and pellet smokers. I also like to cook around 250ish. So I feel like I was in the same boat you are. Here are some things I have learned and done to help me on mine.
I quickly learned once up to temperature, they need very little air flow. Way less than I even anticipated. I barely have my slider open, and my top vent is probably a little less than half way. This puts my stock temperature dial at about 300ish, which seems to be about 250 at the grate level. Once I ease it up to temperature, it always seems to climb another 50 degrees after sitting there for about 30 to 45 minutes, so I shoot for 250 on the dial and it will normally climb up to the 300. Enough about temperature control I guess.
I don't need much smoking wood, the lump seems to put off a real nice thin smoke that keeps me happy.
I am not overly thrilled with stock vent cap, since it rains a lot when I am smoking it seems. So I bought this
[ame="http://www.amazon.com/SmokeWare-Vented-Chimney-Cap-Green/dp/B00G8SAMII"]Amazon.com : SmokeWare SS Vented Chimney Cap for Big Green Egg : Grill Accessories : Patio, Lawn & Garden@@AMEPARAM@@http://ecx.images-amazon.com/images/I/41n1gLgWqEL.@@AMEPARAM@@41n1gLgWqEL[/ame]
It also shuts down the smoker fine without needing to put that ceramic cap on. Smokeware makes some neat accessories, I also have one of their grill grate/plate setter holders that hooks onto the legs of the nest.
Speaking of shutting down the smoker, make sure all vents are closed up good, just a little air keeps this thing going for a long time. It can be forever until it cools down enough to put a cover on. I purchased one of these covers for mine, and I love it
[ame="http://www.amazon.com/gp/product/B00GFST566/ref=oh_details_o01_s00_i00?ie=UTF8&psc=1"]Amazon.com: Cowley Canyon Brand Big Green Egg Cover for Extra Large Egg: Patio, Lawn & Garden@@AMEPARAM@@http://ecx.images-amazon.com/images/I/41-e-U9LbWL.@@AMEPARAM@@41-e-U9LbWL[/ame]
I read that you are suppose to make sure all the circle vent openings in the charcoal grate are open too, they tend to plug with ash. Though this seems to be less of a problem with the XL because its charcoal grate is much larger with many more holes. To make it easier to get at these holes, I crafted an expanded metal charcoal basket that I can just pick up and shake out the ash, clean the holes, clean the ash out of the bottom , and start cooking a lot easier. This may not be necessary, but it helps me out.
The cooker will freeze shut on you in cold weather!!! This sucks, there is a youtube video I found that shows how to get it open if you need to cook without tearing apart your gaskets.
I think this pretty much sums up my experiences so far.
