
I know... .177 vs .22...

If you own a TX200 there would be no difference in accuracy between the pro-sport and the TX200.
The barrels are the same Lother Walther, obviously the full length TX200 barrel is longer but all the AA, springers share the same barrel type including the prosport.
The TX200 and the prosport share the same trigger,,,barrel type,,, spring and rear guide,,,, the only difference is the cocking lever arrangement on the prosport.
The shot cycle is the same, accuracy is the same,,, the Prosport has extra delrin bearing buttons on the comp tube this is only to make the cocking effort easier as you are pulling the comp tube and spring backwards on the prosport which takes more stress on the alloy cocking lever.
The prosport is for looks only,,, it is easier shoot because of the automatic bear trap... stunning rifle indeed... this comes at a price though...
Your only benefits with the prosport are looks and automatic anti bear trap, it is easier and and faster to load the prosport as no messing with manual bear-trap fitted too the TX200.
The TX200 has stronger cocking arm and linkage with all steel construction. There are more linkages complex parts and engineering gone into the prosports hidden cocking lever too give it the good looks, the stock also has more art work... this pushes up the price of the prosport well over £500... stunning rifle indeed though.
Sometimes less is more,,, the TX200 has been know to have achieved 40,000 shots with only a new spring and guide and piston seal... strong rifle with simple all metal cocking arm and parts.
You would only experience any sort of benefits in flatter trajectory and easier long range shooting if you try .177 caliber in ether the TX200 or Prosport.
and more pellet choice and cheaper pellets if using .177 cal.