I have done some work with the two Bowies from Ontario (Survival, and Marine Raider) both of them are nice knives that are easy to sharpen, take an edge well and hold it for a decent period of time. The Survival is much lighter with a more neutral balance than the Raider. Primarily because its flat ground and much narrower.
The Survival workes better on light work like slicing, limbing and brush cutting than the Raider as it will fatigue your wrist a lot less. The Raider is much better at heavy chopping and it is in improvement about 3-4 times over the Survival in this area. The Raider would also probably be much better at prying and other such trying tasks.
I don't like that fighting guard on the Raider as for heavy utility is a negative, the plain handle on the Survival is nicer.
Both of the bowies have a rather nice feature and that is the knife gets thicker near the tip and the grind gets much more obtuse (it goes up to about 35+ degrees per side). This leaves a tip that should be very strong for heavy utility work.
The blades on both are very stiff, less flexible than the TUSK. Holding the Survival in both hands, one at the handle and one around the blade tip I can flex it slightly but not much. The Raider is much stiffer.
Both knives I have belong to Rusty and he has sharpened the top of the clip point on the Raider. This is actually a functioning edge and I have used it to do some limb clearing. The geometry is wrong for reverse heavy chopping (I don't know why you would want to do that anyway), but it would be nice from a utility perspective as an edge to do really hard cutting with (bone, metals) and leave the full cutting edge on the other side unmarred.
The only negative aspect I have found so far is that the handles can be a problem when your grip gets weakened from fatigue. When you are nice and fresh they feel very comfortable and they work well. However when your hand is tired and it starts to slip around on heavy impacts, those little groves in the handle do a nice job at abrading your skin and that hook at the pommel digs into your palm quite nicely. Look at the MD ATAK handles for an example of how to make a grip with excellent retention and comfort.
As I work with them some more I will refine the rather vague comments I made above and put the details up here :
http://www.physics.mun.ca:80/~sstamp/knives/ontario.html
Ralf, if there is anything specific you are interested in just let me know.
-Cliff