"Number of cycles at a chosen SOC range might be a better way to compare them for intended use, haven't got into that"
Glad to see some math on that! Your RVer would need to estimate how many cycles he is likely to use over the expected years as one of his planning factors.
One of the Li brands said they use 70% loss of capacity for its cycle count. ISTR some AGMs or Wets use 50% loss for cycle count. So that would make the Li even better using 70 for both.
This is about building a set of factors to consider in the Li decision, rather than just going with an expensive fashion. Some good factors raised so far. Who's got some more?