Interesting that you say that because the majority opinion is that the Highboys are very neutral, at least when recapped.
Neutral compared to what ?? ... I think maybe it depends on how much gear you've actually owned or listened to ..
People like what they what like, and they're particularly popular on this board and with Vintage fans ..but the Rectlinears never have been, and never will be considered a neutral or high end speaker .. they're certainly not comparable to classics like the Vandersteens or Snells or any number of others ..
I bought the Rectilinears when they were new in the 70's, But I moved on before I was 18 .. and that was hard-working teen.. I earned it myself money, but there were a lot of better and mostly more expensive speakers ...
They used mid-grade drivers that suffered from early breakup if they were cranked and the 2.5" cone tweeter that they use was still common when they were new, but even then everyone was moving toward domed tweeters of a smaller size which were considered superior .. Their bass was plentiful, but peaky at certain frequencies .. They also suffer from significant baffle effects which were just becoming a consideration back in their day, and the idea of imaging hadn't quite even entered the conversation yet ..
Enjoy them .. I bought them, thought that were good speakers for the money, and obviously liked them, but recognize that they may be limited, compared to more expensive higher quality speakers.. ..
Mine got replaced by a pair of AR LST2's, once I had earned enough $$ to get my hands on them ..