Lifter Swap, is it worth it?

Leave them be. They are a quality product unlike a lot of crap being sold today. It MAY be possible to gain a few HP on the top end, but lose MUCH more on the bottom.
Overall you car will get there faster with Rhodes lifters. Biggest complaint is noise, which sounds like solids and means the lifters are working as designed. Also takes some of the "cruise night" lope out of the cam and smooths out idle.