I've got a pretty heavy lobster 853, and rode a mate's alloy lobster, with much lighter gear on too. Got to say I still prefer the steel ride. Funny you use the word livelier, as alive is how many (inc. myself) describe how steel rides compared to ali. It has a zip and zest about it. Ali is dull. Esp. important as you settle into a bike and get used to it over time. Ali just starts to feel dead in comparison to well designed steel frame. Ali is more clinical, but also more wearing on long rides and lacks character and a fun feel that flows with you. If you care about weight / speed, just lose a couple of pounds form the belly and you'll be healthier too! Also speed differences tend to be noticed when jumping from one bike to another, but over time you don't notice them. But you will always know you are on a quality steel bike.
Look, I know what you mean - I've had loads of nice steel frames over the years and there is a certain 'zing' to them.
They do tend to feel comfier on big day rides, and the spring and give of a nice steel frame can make them feel more involving.
However, the right grips, bars, tyres and seatpost can make an alloy bike almost as comfy as a steel one - and that weight difference isn't to be sniffed at.
I've always been a bit of a steel snob, but after riding Ms Spanner's bike quite a lot over the last few years things aren't as clear cut as I once thought.
I reckon design is more important than material, tbh.