I bought D as I am 5'8" 180lbs. They were not that tight on me. I'd have liked more support thru the top of legs to knees.
Yes,  I too stuck my finger thru them in a few places & they ran. Would not buy SPANX again. They were comfortable standing up but the fabric dug into my skin on my rump & the back of my legs while sitting down & I had a pair of Sheer Energy B Pantyhose on beneath them trying to get more support.  I've always worn Sheer Energy Pantyhose & they never hurt my skin.