I own both the TF40 315 and the 100P (2018 model).
Over all the 100P is more something on the boarder of tweener land (the Speed Pro being similar in that respect). I feel like it might be better for someone coming from a Pure Drive or similar rackets and wanting to step in the direction of control. The 18x20 pattern on the 100P could be a little missleading, as it is very open and more so than some 16x19 rackets. However, the extra strings does increase the predictability of the stringbed and control compared to other 16x19, 100 inch rackets. In total it might have the playability you would expect from a 16x20.
The weight and balance is also very polarized. It has that 305 unstrung weight but with a 7pts HL strung balance. Other 305 rackets usually has that 3/4 pts HL strung balance. This makes it swing whippy but still has some weight coming through at contact. However, the whippy nature of the racket (and missing some weight at the middle of the racket i feel) combined with the very open 18x20 didn’t give me the ball flight i was looking for in a 18x20 racket. Felt like i got too much spin and not enough of that «straight line» i usually have with 18x20.
the TF40 is on the other end as far as 18x20 goes. It’s the densest out there, along with the TC97 18x20. Very low ball flight. Feel at contact is slightly modern. Maybe something in between Pure Strike and Ultra Tour/Pro. Power level from the layup is also one step above Ultra Tour/Pro (but nothing for free). Directional control is excelent and with a thin shaped poly ( i use Tourna BH black 7 18 gauge)i get enough bite on the ball to whip up enough spin.
The TF40 315 kind of feels like a more forgiving/modernized 6.1.
just remember that these are my personal feelings about the rackets, and the next person might disagree completely