should I switch to sleeveless wetsuit?

Not an answer to your question, but how far are you pulling up the sleeves?  In order to have most suits fit properly, you will need to have the cuff about 1/2 up your forearm.  If I don't take the time to get the sleeves pulled up far enough, I can feel it in my shoulders within the first 100-200m of swimming.

Shane

I know exactly what you mean about feeling it in the shoulders. I am a strong swimmer and have tried a few full sleeve suits to no avail. Trying to recover with sleeves takes more work. I think the stronger swimmer you are the more you feel it. I say this because the people that tried to sell me on the full sleeve suits were not strong swimmers.

I have an Orca P-Flex Sleeveless and love it. I've had no regrets and have used it down to about 60 degree water. 

Hope this helps.

x whatever on putting it on correctly, but here's another tip.  Once you make sure it's high enough on your hips and all the way up your chest, etc.  either when putting it on or after, twist your arms so the natural correction of the rubber pulls your arm forward in a swimming motion.

I am a strong swimmer, and prefer to swim without a wetsuit in any case, but when I have to this removes any shoulder fatigue that I have experienced.

Yeah, see, I have a long sleeve one, which is good for when the water is cold - but down in VA, the water is only cold in like April. But for longer distances, i think I'd still want one just for the sake of it (even though I'm a good swimmer), as long as they are legal. So I might try to nab a sleeveless one. The sleeves are fine and I know the thing fits, but I feel like the sleeves get in the way a little. With sale and a gift card, I paid $55 for a $300 wetsuit, so I don't mind having two at some point The race I was supposed to do in April definitely needed the long sleeves.