Indian River Backcountry canoe or Ultimate 145 Tandem

Which of these two would be more stable and which would be easier to paddle? The Back Country model is a tunnel hull. I already have it and used it just once. It paddled fairly easily, but it did not seem very stable. IIRC, it has better secondary stability. But it sure felt tippy. I did not push it to find out about the secondary stability, as my daughter was with me.

The Ultimate 145 Tandem is a 2011 model. Current specs tell me it weighs almost exactly the same as the Indian River canoe, with jut one of the two seats installed (59 lbs for the Ultimate vs 60 lbs for the Indian River). I would only install the second seat if someone else were going with me. But I have no idea if a 2011 model would weigh the same as the current model. And I don’t see a phone number to call Ultimate.

Any advice or pointers? Stability, weight and easy to paddle are my main criteria. In that order.