The stock skidplate is thin plastic and protects against skidding only. Any significant bashing against rocks or logs etc. will dent the frame underneath because the plastic isn't thick enough to disperse the force of impact.
AXP Racing's 8mm XTrem plate provides bash-protection, as well as greater side coverage and an integrated shock linkage guard. I've had one on my 2016 Xtrainer for several seasons now and have been very happy with it. I'd definitely buy it again if I had to make the decision again.
TM Designworks has since introduced a similar thick plastic plate with linkage protection. I've heard, but not verified, that the TMD plate is a bit easier to mount and remove than the AXP, but I haven't really had any problems with my own AXP in that regard. TMD plastic is a bit different than AXP, but also tough material. I've been abusing a TMD rear rotor guard for several hundred hours now and it's held up well. If it matters to you. AXP plates are made in France, and the TMD plates are made in the USA.
Below is a pic of my Xtrainer with AXP Xtrem plate (and TMD rear rotor guard.)