We bought a 22 XLT specifically trying to buy something with the least amount of electronics possible due to lots of bad luck lately with buggy software on vehicles. We hated how it looked, but decided we'd customize a bit with the money we saved by not going with the higher trim levels. That aside, we replaced the stock 20's with 20's that had +18 offset. We went slightly larger on tires - 275/60. This config has just enough clearance, but doesn't look like I could go any bigger or the tire will likely rub on the front splash shield.
In my opinion, I don't like how Exp's look in stock form with the wheels inset so far. +18 looks perfect to me, tires end up just 1/2" or so proud of the fender. Yes, you get a little bit of extra splash on the side of the vehicle, but very little. Not noticeable to us. We think the vehicle rides like crap from the factory, so didn't notice that it really got any better or worse with the new wheels.
BigOleFordFam mentioned durability problems by going smaller - wrong. Bigger tire sidewall transfers less impact to suspension components. I was a mfg engineer on F150 for years. Around 2006 we were adding 20", or maybe 22" wheels to the lineup, and I took part in dozens of meetings reviewing potential changes that would need to be made to the suspension and steering systems to deal with the higher impact forces. You'd be amazed how much that smaller sidewall beats up the suspension.
And Discount Tire did well for me. We bought the wheels from Custom Offsets. Balance as delivered was horrendous. I took them to DT to rebalance and they did a great job.