Expensive tweaks-are they worth it?

The Walker HDL's do make a difference. Whether that difference is a good thing or a bad thing is purely subjective. Thing is, $300 will buy you a fat stack of records. Something to think about...

The Walkers do make a difference on my dynamic system as well, although I think they're expensive for what they are (not the improvements). The designer of my speakers did a measurement at the tweeter with the HDLs in and out of the system and there actually was a measurable smoothing of the treble output. The room lenses didn't work for me, but my system is almost an omnidirectional one, that probably has a lot to do with it; on a more conventional speaker system my result may well have been different.

I too gained a significant improvement upon using the Walker Audio HDLs on my Thiel speakers. They are very much worth the price I paid for them.
I have it about 6 months on my speakers and I forgot that it's in there. I tried to take it off one time when I was re-positioning my speakers,the result was unbearable,I did not even finish listening to one track and I have to put it back in.
It's like a lot of good things that we have and take for granted, we will never know how vital it is until we loose it.

I think expensive twerps are always worth it...oh...sorry,
you said tweaks.. Actually, some of the least expensive
are the most "worth it".
1. Make sure your cable TV feed isn't introducing DC voltage on your homes AC ground.
2. Level any mechanical source...ie: turntable, CD player
or transport.. and level the item..not the shelf they
are upon. If you don't "get" this one..try walking
uphill or downhill..and then on level ground.
3. Keep all cables as short as possible...if this is not
of merit..then why do "upgrades" of high-end gear often
talk of "a shorter signal path"... ie: more wire is
more ohm's, inductance...etc.
4. If you live in an area with decent FM stations..make
sure you have a good( if not great) tuner. There is
no better way to learn of new release or re-release
music that you may want to ad to your system..and many
towns have college stations that broadcast very good
signals and music mix.
Just some ideas on "other" tweaks....

I use both and find them beneficial in my system.