I understand they have developed over the years but I'm my experience with them I won't use them again iv used both a 25 highflow and a td06 and I would much rather a td06. To the op the 20 setup will work if you use a rb20 tps and buy a td06h-20g 10cm or td06sl2-20g 10cm. I used the td06h 8cm on a rb20 and it made a very fast car and fun to drive. All that really needs deciding on is if you want internal gate or external gate