Hey Gina, they size out like a Carhartt. Which would be running about one size big. I got my hubby the 2X tall, he's 6'1", 295# and the length in the arms and everything fit him great.
They aren't too heavy or bulky, but with the insulation they are very warm! We've been running about 18 degrees by day with a terrible windchill, but mine has kept me toasty warm. They are made really well and of durable fabric. The only con I can think of on them is the hood doesn't lay real flat. That might annoy you if you had a cowboy hat on, but other than that, it's ok. I figure it should relax after it gets broken in well.
I couldn't believe what a good price they were! The Carhartts similar to them were like $60-$70 bucks!