i would agree with hilldodger….as a zindane zindane sweaty bloke i find……
merino is wet through and sodden in 10 mins, waste of time and money and apart from my smart wool top nothing has lasted kona top turned to felt, (highly recommended on singletrack review) and a few other brands high end went the same way, as a sweaty devil the fabric cannot deal with the sweat and i have always felt cold when i stop. However i use a base layer manmade with the smart wool top and that has been great for xc skiing and other such stuff.
Merino mix….the best i have used is ground effect submerino lasted a decade and is pretty effecient in all departments.
bamboo….pretty much summer stuff, my kids rate it more than me.
man made….simply the most effecient way to move sweat. I would recommend
decathlon skins compression tops
aldi specials the winter one last year fab
craft stuff very good and try TK MAxx
cannondale some of their stuff was brillant
helly hansen as said above
under armour got a couple of tops and impressive
nike is pretty ropey these days as is adidas
just my swaety bloke observations 😉