The TS-430 is over 30 years old, where as the 718 is a newer rig. If they're both operating well, in nice cosmetic condition and the Kenwood is priced less that the 718, perhaps the TS-430. It offers a nicer fluorescent display, a real S meter and that great Kenwood transmit audio.
If the TS-430 includes some options like the FM-430, FM board, the YK various filters and maybe an MC-60A desk mic, it would be hard to resist.
Good luck and have fun...
I have had a 430S since it was new in the early 80's. You cannot beat this radio for receive selectivity and transmit audio. Looking at the specifications, the 430 beats the 718 in almost every category. I love this radio and I just wanted to pass along my feelings on the rig. Good luck with your decision.
Mike
Nonstop screaming into the microphone! The rig must be capable of transmitting "You're 5-9" for many hours on end.What is contest level usage ??
I heard that there are a few radios that can handle almost any QRM or QRN. However they are used by the government, and cost a small fortune.