Well I did say this was a contentious issue, and it does tend to polarise users.
Basically I think it comes down to a personal preference, your style of planing, rather than the plane iself. And also to the specific demands of the timber.
There are just too many planes around that would contradict the "heavier is better" brigade (such as HNT Gordon, Mujingfang, Clark & Williams, ECE/Primus, amongst others), and the "fact" is that these planes perform superbly. But would they be better if they were heavier?
Which is easier to use: my Stanley #7 or my HNT Gordon Try Plane. I enjoy using both, but they are so different from each other that comparisons are difficult. The #7 has a wider blade and extra mass, and the greater momentum is actually needed to move the plane down the board. The HNT Gordon, being lighter and narrower, with a sole that has much less friction, takes a finer cut with a smaller mouth, and so seems to glide along with little effort.
I have quite a wide range of smoothers from which to choose. For example, I could use my LV LA Jack as a smoother on a difficult-to-plane hardwood, such as Jarrah. Or I could use a LV LA Smoother. Will the momentum of the Jack provide some advantage over the smaller mass of the Smoother? I don't know, and I think that I will do some comparisons when I get to test the new LV LA Large Smoother. At this stage my Jack is set up as a panel plane and for the shooting board.
All I can say at this stage it that I believe that it is the final quality of the surface that counts, and if we are talking about final smoothing, then a smaller plane is what I am more likely to turn to at this time. I am reminded of the length of traditional coffin smoothers, which were about 7". The absolute best plane I have for removing tearout and leaving a polished surface is a 4" long Mujingfang mini smoother (60 degree cutting angle). But you wouldn't want to use this dinky plane on a large panel. Further, different planes (with different cutting angles) perform better than others on different timbers, and I will also make a choice on that basis. Weight does not come into the equation. What I am saying is that I choose a smoother for the task at hand, not choose one since I believe it is better than the others at all smoothing tasks.
I would be interested in hearing from other why they prefer their smoothers, and how they decide which to use.
Regards from Perth
Derek