> An academic reactor or reactor plant almost always has the following basic characteristics: (1) It is simple. (2) It is small. (3) It is cheap. (4) It is light. (5) It can be built very quickly. (6) It is very flexible in purpose. (7) Very little development will be required. It will use off-the-shelf components. (8) The reactor is in the study phase. It is not being built now.
>On the other hand a practical reactor can be distinguished by the following characteristics: (1) It is being built now. (2) It is behind schedule. (3) It requires an immense amount of development on apparently trivial items. (4) It is very expensive. (5) It takes a long time to build because of its engineering development problems. (6) It is large. (7) It is heavy. (8) It is complicated.
SMRs and MSRs are in the academic stage at the moment. We don't know what they will look like at the end when they are actual products, but there are technical and practical reasons that they haven't been tried before now, so I think it's only prudent to withhold enthusiasm until we have data on their characteristics and potential.
Back in the 80s, we had PV panels in hand, and knowledge of silicon tech curves that could predict the rosy future we live in today. SMRs are a bit more shaky.