Hi

The Kiwa filters and audio upgrade are definitely worth the money. I
chose the
6KHZ / 3.7 KHz combination (I couldn't decide between 4 and 3.5 KHz
for the narrow, so Craig from Kiwa sent me one in between). The
modules are easy to install and really improve selectivity. I bought
my FRG-100 new in Jan 2001, so mine had the improved filters and yet
the Kiwa filters still improved things as they're tighter.

If yours is an old model, you'll hear a massive difference between the
original and Kiwa filters. If it's a newer model (post 1995, I think),
you could probably get away with swapping just the wide filter for an
LF-H4S from Kiwa.

I really do recommend the audio upgrade as it clears things up a great
deal, making speech more intelligible, even with the narrow filters
setting.

With Kiwa filters, my FRG-100 performs as well as an Icom R71E with
various upgrades, so it should beat the Grundig into the ground. For
comparison, I have a Sony ICF-SW7600GR, which is similar in
performance to the Grundig. The FRG-100 and Icom are both in a
different league to these portables, especially in terms of
selectivity and overload resistance.

Enjoy your FRoG. It's a great radio and you'd have to spend a fortune
to get anything significantly better.

Cheers

Andy