Well GICON there's a big difference, I too used to wear cotton shirts years ago.
For starters these are SPF50 and fluro bright, so you can been seen and wont get sunburn.
The fabric is a special microfibre that "breathes", they call it moisture control, just doesn't feel like a wet rag hanging on you (its always hot here).
They are quite long in the body so the bottom of the shirt doesn't ride up and let sawdust down your dacks.
Also, I found it washes up really well and the sawdust doesn't get too stuck in the fibres.
I take 2 to work and if one gets really sweaty I just hang it up somewhere grab the second one ... they do dry out reasonable quick.
Also, they hold their shape really well and don't fall apart in the wash ... no shrinking either.
T-shirts tend not to have a collar and you get burnt on the back of the neck. So, you can buy bright T-shirts but once you work in these you'll never go back ... but beware, there are lots of BS imitations out there ...
It's gotta be
HARD YAKKA brand.
OK VH, you got a deal, I'll PM you with my details and vice versa.