The 690 has an internal oil sump and tons of ground clearance, since the V-configuration of the cylinders and the shorter stroke would make a twin less tall you could make the sump bigger without losing any clearance.
And while many people were complaining about the lack of frame tubing below the engine at first, I have not heard of a single broken case. Install a good skid plate that is supported by two beams off the main frame up front and by the frame in the rear and it will be fine.
Proud member of the HUSABERG ADVENTURE TEAM!
12 690 Enduro-R, 12 Husaberg FE570, 09 KTM XC-F/ 450 RFS hybrid, 07 KTM 450 SMR, 09 BMW F650GS twin/F800GS hybrid, 03+05 YZF-R6