I'm fairly well qualified to comment on this I think….
I did 30,000 miles on a 955i Speed Triple and swapped it for a Ducati Monster
Triumph – Like a velvet sledgehammer! Beautiful creamy power from tickover to red line with an astonishing mid range wallop and a howling top end kick. The engine is nearly faultless, apart from being a bit fluffy at the bottom end on part throttle (think roundabouts). 42+ mpg easily, 150+ miles on a tank, silly relliable, but not cheap to run by any means. No cheaper than a Duke, put it that way. Handling is good, but heavy and steady rather than light and nimble. Also quite high up. I liked the semi sporty riding position. Feels like it's hewn from granite. Superb build quality too. Mine looked good after all those miles and living in the garden for most of it's life. Had an apitite for light bulbs and cables but that's about it really.
Monster – I bought a new 696 when they first came out and kept it for just over a year. Only sold as I needed the cash. Tiny, impractical, full of charcter. The engine, although never as fast as the triumph was utterly, utterly wonderful. It just begged to be revved, thrashed and caned. It made THE most incredible roarty throaty growl right under your chin (standard cans on all my bikes) utterly smooth and glitch free, but needs a 1 tooth smaller front sprocket to make it less jerky in town. Handling was light and noble yet perfectly stable and on the sporty side of things. I could chuck it round like a little BMX. 52mpg when thrashed, 140 miles on a smaller tank. Better brakes too – Radial Brembos
Which bike was best? Well the Trumpet was a wonderful bike, took me to Italy and back easily and was doubtless big, comfy and faster. The Duke was impractial, tiny, and needed to be ridden hard. Not quite as well built either. Both brilliant bikes in their own ways.
Which bike do I miss? Easy! The Monster. I used to just sit and gaze at it in the garage. It made me laugh out loud when it roared at me. I could domiate it and throw it around. It egged me on to go faster without ever getting out of shape. A wondrerful, incredible little bike and I was smitten.
If you want a bike to make you smile and be happy, get a Triumph
if you want a bike to make you laugh and fall in love, get a Duke. No question.