HFTs or more fuses

I have the RED fuses installed and HFT"s in my system.
I would add HFTs. You really get a good effect with 15 ( three boxes).

If possible order three boxes or at least two. Easy to attach or move, or remove.
 You get 30 days to try them and see if they take your system in the direction you want. Plus no break in time!

David Pritchard

If you do not have a well treated room, go for the HFT's first. They make the biggest improvements in rooms that have sonic issues.

I just spent a chunk of change on new speaker cables. So, I only have $300 to play with. Are you telling me that one box of five does little to improve SQ? 

If you decide on HFT, checkout Audio Magic Bells.     They replaced my 3 packs of HFTs.    Better tone, more effective, less expensive ...

Audio Magic Bells

If you have just got the red fuses, do they have a 30day trial. 

It might be more worthwhile to get the black fuse to try as it seems to suggest that they are much improved over the Reds.

As for HFT's, placement and knowing your room , effects of sound and room treatments will key to obtain the greatest benefits or notice not much. The HFT's are effective but a knowledge is required.

Not knowing how your room is, otherwise, changing the fuses might be a more greater improvement - more like changing up a to higher level cable of the same manufacturer.