At the time I was trying to find another method to replace my Dowelmax and 10mm dowels, no problems with joint strength or anything except it could be very time consuming on assembly, I think on one job I used 96 dowels and so I started to look around. The Domino looked like a solution, albeit a very expensive one so when I came across one in an FFX sale I brought it along with a box of oblong dowels. Quality is not outstanding when compared to other tools but it does makes nice precise oblong holes, the problem is in locating them precisely and is why I refer to it being like a riffle with a bent barrel. When comparing the precision of the Dowelmax to the Domino in location of holes there is no comparison, the Dowelmax is way more precise so next I brought the Domino alignment jig from FC tools which is great for sheet material and gives the domino the precision it needs. But on larger size wood which I mostly use then it failed to meet expectations, the Dowelmax has always exceled at this task as can be shown in this imageYou mention you have the Domino XL700; I love it. Never had any issues.
So now I am thinking of that Jessem dowel jig, maybe that will deliver faster results but I still play with the Domino hoping one day I can use it and get the results I want.