I just called to inquire about upgrading my service (currently 2 Tivo Premiere boxes and an HD converter box). I asked about the T6 because, well, it's the latest and greatest. I was told that in order to get the T6, you need to setup minimum of 5 TVs (I would imagine 1 main box and 4 Tivo Mini boxes).
That seems really odd to me that RCN would limit the number of people who can get this to anyone who has at least 5 TVs to setup. The website doesn't mention anything like that at all and says the T6 bundle is the T6 and one Tivo Mini.
When RCN installed my T6, it was either with one or two Minis [I forget now - but, at only $5 for each additional Mini. I now have 3 Minis (and a few iPhones/iPads to keep my T6 busy)]. You should be fine with the T6 bundle as listed on the RCN website.
The T6 is really the greatest. I am sure you will be happy with it.
It seems very odd. I think you can actually add up to 8 or 9 minis, but you can't watch live TV all at once. You can only watch live TV on (6 minus number of shows recording) minis.