Any thoughts on this suit in a HIM or IM?
It’s made for bike only. Do you plan on changing for the run?
No. So my guess this will be uncomfortable running in?
Yes and swimming in. It was made specifically for TT use only and will be very tight fitting. Get a regular sleeved tri suit instead.
Cycling TT skinsuits - at least the good ones - are cut for cycling position. They pull your shoulders forward and in and are typically quite short in the front because they assume you will be in a hunched over position. You do not want to try to run in a suit like this. For an Ironman, depending on how quickly you can get it on/off (they tend to be very tight, so especially with wet skin, this could be a real issue), you might consider it if you changed for the run. But it’s debatable.
In 2015, Jan Frodeno used a custom skinsuit made my Lexi in Kona on the bike, who makes cycling and speedskating TT skinsuits, and then switched to a two piece kit for the run. But since then, he’s used a 2XU standard sleeve triathlon tri-kit and now is with a new company Ryzon that also makes a tri-specific sleeved kit.
Even if a good cycling skinsuit is faster, I doubt it’s faster by enough to make up for the lost time in transition.