I already have lots of 16-tonners, from the original Airfiox kits through most other kits and many RTR makes. So I didsn't NEED any more, but these have been calling to me for months, and I fuinally gave in when they were likely to sell out. I'm so glad I did! They are just finer mouldings than all the rest, just weightier, needing no further weighting to track through points and crossings so silkily. The usually-unseen details underneath are exquisite, better than I could ever do. can you tell I am happy with my purchase yet? Thanks Accurascale, very much.