I don't think so! Isn't it important if an engine is very slow and if this is going to make a game with a lot of stuff, very slow? I think that it's something very important! Maybe an engine could have a lot of features, but if you make a game you see that you have to remove some graphics or materials so that your game can run on a decent computer. Do I say anything that is wrong?
Yes unfortunately you did. It's clear that you misunderstand me. It would certainly be nice if one could know how far you can push an engine, but this simply isn't something you can reduce to a simple scale suitable for a catagory in a table. You see, it depends highly on what you specifically do with it. For example, the scene graph I work with at my job is more than adequate with respect to the scenes we are rendering, but it is relatively slow at node traversal, so a scene with many nodes may render slowly even if there aren't any more triangles or objects. Quake 3 is extremely fast, but it's speed is dependent on you constructing a static scene with large rooms separated by small doorways to suit the portal rendering. These are just a couple of very simple examples. Do not misunderstand and think that you can special case these engines with a small note or somesuch.
The short of it all, is that while it may be nice in theory, it just isn't a realistic possibility.