I got the thunderpants for Christmas and my feelings are the same.
When it's heinous, wet weather they are like armor, they help me feel like I can face the ride ahead. But that's the only time I wear them. Too heavy and stiff for general riding where it's just a little too chilly for shorts.
The neoprene cuffs are the best part. Highly recommend against cutting them, they really deflect a ton of crap off of my shoes.