Have L401 and like the extras but every morning have to do a hard reboot because when turned on I have sound but no picture. Holding down power button and letting it reset fixes the problem. This has happened last 4-6 mornings and once after being turned off for an hour.
I think you'll be fine. I have Tivo connected to a 6000 and also a 510 hooked up to the same tv. Just run one line to Tivo and the other direct to the tv. That's what I did.
