I originally bought the Sarris Bones Single -- and it was junk. The straps kept coming loose and I had to readjust them with almost every 20 mile trip. I did not feel that my bike was at all safe or secure with it. In addition, the bike was far too close to the car and I got a number of scratches from it.

Then one day I opened the trunk with the bike attached and, when I set something down, the trunk slammed shut and one of the thin little straps snapped.

So, I traded it for a Sarris Bones three which I like a LOT better.

The straps are much wider. The buckles are heavier and hold much better. In fact, I have had it on for several months and it is still tight and secure. In addition, the lower feet rest on the top of my bumper so it seems to be more secure because the weight is being born by the bumper rather than the straps and buckles.

In addition, the bars that hold the bikes are individually adjustable -- so it holds the bikes whether they have a level top tube of not.

My only complaints with it are:
-- The straps the hold the bike itself are thick plastic and they catch on the cables that run under my top tube when I put the bike on or take it off.
-- The bike mounts are too close for 3 bikes -- but it works well for two.

And, I still need to use a tie down to secure the front wheel from swinging around.

But, all of my complaints about the 3 bike rack are really pretty minor. All in all, I am happy with it.

I suspect the 2 bike model would fall somewhere between the single model and the triple.

If you get one, I would recommend getting the triple. I suspect the straps & buckles will be higher quality and more secure and it will get the bikes away from each other and your car better.