I had a terrible experience with Tri's.
Did a few times and everything was great, then one time I had the pin in, all was good, but right as I started to push the oil I dropped the pin completely. It stayed in but the weight of the pin and oil made it fall (not out but while in it rotated down to hanging) and the pin inside me kinda cut through some of my muscle; just a little sore that day but the the rest of the week it was swollen and painful -- took a couple weeks to completely heal.
Nothing against tricep as a site, but it was just my own error because I was not comfortable or stable reaching across my body with my non-dominant hand. I fucked up and fumbled it and it sucked.
That is why I like thigh so much -- I can just sit down and everything is right in my lap easy to see and easy to reach.