If you can't build a little house for your little dude and have him drive a little car to his little job, it's not comparable to the Lego brand. There's a sort of imaginative vicarity at play. This toy is far more abstract.
Perhaps it would be more appropriate to say that Qubits are the abstract thinker's legos? Even that would be a bit of a stretch. However, I do see that there is some very interesting potential there. I cannot speak to how well those pieces will work. Will they hold together like Legos do, or will it be frustration-ville like Mega-Blocks. (I only speak from personal experience, maybe others had better experiences with Mega-Blocks.)
I had both legos and Meccano/Erector sets when I was growing up. Those two toys, though complementary, filled vastly different roles in my game play. Legos filled the practical, down to earth area, where I could build cities, create stories for my people, etc. On the other hand Erector sets taught me lots about engineering or architecture. Even following the instructions to put together a pre-conceived set was very instructive. I also learned a lot about prototyping from them. You would build something, say a car, and the first instance it would come out blocky and ugly, but functional. Then you would see how it could improve aesthetically or performance-wise. You make those changes, which quite often required taking most of the car apart, and then you would see others. Quite a good lesson in R&D at least at a base level.
Qubits seems to combine some aspects from both those toys and the result appears to be a third niche in the free-play type toy market. Qubits is rather abstract when compared to legos, and even erector, though it definitely has the architectural potential like Erector. However its pieces are more lego-ish in that they appear to be large, plastic, multi-colored, and most importantly don't require tiny screws and special tools to put together and take apart. The result, I think, will be a toy that is far more popular at school than at home. Teachers will use it to model shapes, concepts, etc. This could continue into high school where math, chemistry, etc classes could model things with them. (be warned I am neither a mathematician nor chemist.) I think the toy will be successful in its niche, but it is not a cooler lego, it is entirely separate. I am curious about a couple of things.
1) They already use the triangle shape as their basic object. I had to learn that it was the best shape for building sturdy structures on my own using Erector. Is making that an assumption instead of a learning point a negative? Tentatively, I think that depends on the goal of the toy.
2) I am not sure how much traction it will be able to grab outside of learning environments. Legos (and for some of us Erector) were a toy that allowed imagination play, which was real play. This toy seems to be mostly learning disguised as play (not a bad thing.)
3) Did I miss the picture of a gun, cause those shapes are just itching to be built into awesome unrealistic weaponry. Its the first thing I would build. (maybe that says something about me...)
EDIT: formatting.