They are tough on clutches.
My experience, bought a CK Performance 'Stage 2' 200-4R for a NA 400ft/lb build ($2300). After two years we threw it in our first G with a mild turbo build (mild - 450whp/520wtq). After 15K miles had to have the steels and clutches replaced due to it started making the 1st-2nd shift in mild manner rather than the usual bone jarring shift. Two years later through some bigger power in and upgraded to a billet input shaft. This upgrade cost about $250. After 4 years from original purchase (2 more years) had the pump rebuilt/replaced - 10 vane. Also had a full set of valve body gaskets replaced and another set of steels and friction discs - but this motor is close to 1000 crank and 850 tq. 2 years later again (presently) it's getting another set of steels and friction clutches.
I have the Dr. (Trans Dr) going through it for the 2nd time - will be about $800. But it's well worth it. Maybe a 4L80 would take more, but maybe not. Every possible billet part available for a 200 is in this thing and it's for less than $3K. Many will consider that too much, alot, or crazy, but for a daily non salty driver at 850 whp this not crazy IMHO. For a 9 second trans I consider it cheap.
The stock 200-4R will make about 160-180lbs of line pressure at WOT. Ours makes 270 on a bad day. A stock GN governor will make WOT shofts at 5000-5200, ours makes it it at 5800. The stock grocery getter 200-4R makes that shift at 35-3800. The only driveability issue we have is when we make an extremely low throttle position take off at low speed. 1st-2nd will rattle the car. But at 20% TPS it shfts comfortably and over 70% TPS (800 hp) it shifts faster than you can blink an eye and it's smooth as glass. It puts a smile on my face everytime I hear it. And it's a great reason to hear the tires chirp.