Hornady data, minimum and maximum, 1.260" COL for both XTP and FMJ 200gr.:
Unique: 5.3gr. @ 850fps, 6.4gr. @ 1000fps
Power Pistol: 6.0gr. @ 850fps, 7.6gr. @ 1050fps
Speer has their 200gr. TMJ loaded to 1.250" COL, maximum and minimum, and uses:
2400 at 11gr. @ 1059, 12gr. @ 1152
Unique at 6.8gr. @ 987, 7.5gr. @ 1092
For my 10mm Hornady XTP loads, I like the 180gr. I get more energy and velocity, and it tends to perform very well in the G29 and the G20. The 200gr. bullet, in my opinion, may take a backseat to the .45ACP+P 200gr. But the 180gr. XTP is smoking when loaded with IMR 800-X or Blue Dot (be careful, weigh each load, use a trickler or trickler function).
I personally carry a 180gr. XTP loaded with 800-X and it clocks about 1200-1250fps in a G29. Not bad for a small pistol. It will handle hotter loads, but they are not necessary. I'm working up my own 200gr. loads, but I'll be using 800-X and Blue Dot and if they don't surpass the ACP+P in a few key areas, I'll abandon that loading and stick with the 180's. The 10mm can do things with 180's the .45 and the .40 can't dream of.
For a good all around powder for if you don't want to load high velocity rounds, the Viht N340 works well, and it works well in target loads in .40, .45, and 10mm. Great powder and it would meter well (I use this and 3N37 in .40 and just the 3N37 in 9mm --N110 in .357, Viht makes good stuff!).
For hot 10mm loads or for a great range of velocities, Blue Dot or 800-X are the way to go. If you load 10mm and 200gr. XTP's, you'll find yourself wanting a pound of Blue Dot or 800-X sooner or later (I use Blue Dot, but 800-X for 180gr.).
PM me if you want more info.