The refill used is for a Montblanc highlighter which, how to put it, is an expensive highlighter refill. Retailing around $10 a pop, if you highlight a lot of stuff you may have some higher than normal refill budget requirements when using the TiScribe HL. Granted, there aren't a ton of great highlighter refill options like this on the market, but just something that needed to be brought up.
I don't use highlighters in my day to day very often, but this refill works extremely well. It has a nice, sharp chisel tip which makes working in smaller word spaces easier.