you get more rated DC watts with the R, and a slightly lower degradation rate over time (.3% vs .33% per year)… however, the Enphase iq7+ caps the AC output at 290watts AC in both cases; so … the NET output depends on your install conditions and whether either model will approach or exceed clipping limit of the Enphase.
i.e. at a perfect tilt, south exposure, the Neon R will exceed the Enphase throughput capacity more, and basically waste the extra DC output of a higher output panel. If the install condition are such that the R will rarely approach actual DC/AC output limit of 290w, then the extra output MAY be worthwhile depending on the cost differential. The R panels are significantly more expensive because of a higher wholesale cost to installers.
what you really need to look at is the (net cost / TOTAL 25 year (warranteed) kWhr production ) to determine the cost/kwhr of warranted production.
side note is that if the install is at a good azimuth/tilt likely to exceed 290w, then you should probably switch from Enphase micros to SolarEdge string with a high enough AC capacity to avoid clipping.