Morso Squirrel (1410) or Swift?

[malp]

I need to replace an old Morso Squirrel which is realistically beyond economic repair.  Existing flue system is more modern and sound, so looking to go for another Morso, rather than a cheaper alternative which would most likely involve extra cost of a new flue.  To save a bit of money I'm considering the Swift, as all exterior dimensions are identical to the Squirrel making it a drop in replacement.

 

Before deciding I'd appreciates input from anyone who has experience of both who can give a comparison of performance.