Ask your dealer about switching brands. There is such a variation in diameter and materials for lever harp strings that it’s best to check with a knowledgeable source. If you are still unsure, check with the manufacturer. Putting the wrong strings on your harp can put undue stress on the soundboard and neck.
The strings from the various manufactures do sound different. Bow Brands are said to be “brighter” while Vanderbilts are “warmer.”
The best sounding strings are ones that are not false and still have life in them. Old and or pitted strings will not sound nor perform as well as new. Whether you like “bright” or “warm” will depend on what you want to hear from your harp.
I’m not familiar with Boyau gut strings, so can’t comment.