Hi another view.
We had our unreliable Lister JP3 replaced with a Beta Tug in March this year and have done 200 hours since.
It was fitted on wooden engine bearers and we used the same exhaust silencer as the Lister. The 24x20 Crowther prop was repitched to 20x17 which is perfect IMO. On shallow canals 700 revs is sufficient, deaper water allows up to 800 and it really moves on rivers at 1000 revs.
The only down side is the sound, no it is not noisey in fact it is queiter than before but with load at low revs they are very clattery, once at cruising speed its great.
Things i dont miss.
The smoke when doing a lock flight or at other times if it felt like it(I gave up smoking years ago)
The smell in the engine room.
Taking ages to rev up.
Things I like.
Instant power as soon as you wind it on.
No smoke when warm.
Does not use oil or coolant.
Easy to service.
3 year warranty.
Another 3 foot in the engine room.
Oh and this has surprised me, early days but appears to use less diesel.
Less pitch on the prop makes the boat easier to handle in emergency stop and when reversing.
Am I happy YES