I have the T/C Hawken, it's a great rifle for what I do with it (mostly club shoots, rifle courses at rendezvous). It has a 1:48 twist barrel and shoots roundball loads very accurately up to about 75 grains, and conicals reasonably well although I have not experimented a lot with them. Length and weight is comfortable enough to shoot all day for me. I would also like to get a Great Plains Rifle sometime, mainly for hunting with round ball and maybe longer range shooting - because the slower 1:66 twist rate should allow for a faster RB load. Because it's a heavier and longer rifle, it could become a bit tiresome for the club shoots. The Great Plains Hunter has a faster 1:32 twist barrel, better suited for modern type projectiles. That's not really my interest so it would not be my choice.
How you plan to use it will make a difference, but I can certainly vouch for the quality and reliability of the T/C, and it is plenty versatile. But the GPR/GPH models have their strengths as well.