no we just dont like overpowered trash
I honestly would consider the DR more op then the RTR.
When you destroy a sentry with the regular sapper, you're able to collect ammo for the ringer, plus the damage reduction for it is crazy high (same as the phlog before it got nerfed), but it doesn't last forever thankfully.
With the RTR, I would rather have a teleporter get sapped by it rather than the standard sapper, because you don't have to leave your post if your entrance gets destroyed.
I'm probably the only one thinking of the other stuff the engie uses aside from the Sentry, because all I'm hearing from you guys is that it's OP and not giving me that many good arguments for as to why it's op, except that it levels down a sentry too fast.
HOWEVER, for the RTR being OP, I can agree that when it's in the middle of deconstructing the sentry, while in the middle when the sapper gets knocked off, it takes the same amount of time for it to reconstruct rather than for the sentry to recover from the standard sapper. So buff the sentry recovery speed getting reconstructed back to level 2 or 3 when the sapper gets removed.