I think it comes down to your notion of just how significant an improvement in your flying situation has occurred. On UA there are some seats in the E- section that are considered better than most of the E+ seats on certain aircraft types. Add to that the fact that the level of service is no different between E+ and E- and the case gets weaker still.

Finally, IMHO it comes down to a matter of common usage on FT. On FT an “op up” has always meant something quite significant. Something where your flying experience was greatly improved and you were thrilled to get it. In other words, something worthy of posting on FT! I honestly don’t think that the difference between E+ and E- passes that threshold.