I have an 08 2500 extra long and tall diesel Sprinter. I bought it not because I thought they were good, I needed the space for a customer I used to have in my pre FX days. Here is what I have learned so far about the new style Sprinters.
Maintenance can be expensive. The Sprinter is a Mercedes and uses things that are European in nature. Specifically, you can't just go to Wal-Mart and buy oil, filters or even coolant for it. And be fully aware that if you ignore the specs and put in what you think will be OK, bad things happen. You can with a bit of effort find this stuff though. Amazingly, most Flying J's actually sell coolant that meets the spec, Oil can be bought from Valvoline and Mobil to name a couple, just make sure it meets MB 229.51, CJ-4 oil is not OK to use. Wix makes filters so that's gotten a lot cheaper. Changing the oil yourself is super easy so you can save a few bucks that way too.
They are very pleasant to drive. I've been a GM guy all my life and I admit that I like driving my Sprinter (come on FX find me some loads so I can!!). They are a bit challenging in the wind but it is a big vehicle so it shouldn't be a surprise. The aftermarket is starting to have suspension upgrades available, just be careful what you install (especially air springs). Fuel mileage on the new ones is still ok, at around 20mpg. The interior space is unbelievable. I have room for 3 skids and I have a permanent 40 inch bunk sealed off from the back. If I wanted to, I have the room to do jumping jacks up front. I tried once just to see if I could, then stopped right away and hoped nobody saw it.
There have been some issues with the EGR valves. There has been a recall to update the ECM to make the valve work better. A lot of the EGR issue are a result of poor fuel, lots of city driving or idling, and the wrong engine oil. I had no issues so far but had the update done anyways.
All in all, I have had good luck so far, but if GM would make a van this big I would buy it simply because of parts and service cost and things on a GM (or Ford) are a bit heavier (frame suspension hubs axles etc)
PS, the stock Continental tires on them are very poor.