Okay a bit on CTF, or Cut-Through Forwarding, also known as Cut-Through Switching:

This feature was originally intended for advanced managed switches, not SOHO routers that rely on LAN to WAN traffic, and vice-versa. This is why packets meant for certain traffic break (e.g. VOIP/video streams, port forwarding, QOS, VPN).

This is fine for LAN to LAN traffic and SOHO routers that are just APs (Access Points). My testing yielded better results with it enabled, but since CTF really utilizes the kernel, it eats more CPU power and cycles than with it disabled. This also affects WLAN performance a bit, made worse if the general WLAN area is congested.

DD-WRT is not as stable in general at present, but it is worse with CTF enabled. As with FreshTomato, it is generally more stable, even with CTF enabled.