Cary SLP98L upgrades--yea or nay?

I’ve listened to a lot of Cary SLP-98 preamp’s with various mods.  To me in its original form it’s a bit lackluster. Not the most extended highs, nor most extended lows, and not the most detail or soundstage compared to more expensive, preamps, but a really nice fluid, sweet sound.  Definitely a preamp worth upgrading.  The F1 is a big step up. But of course, everybody has their opinion of what is the best capacitor. The big problem is what capacitors will fit in that preamp chassis space.  I happen to really like the Mundorf’s (at least they’re best) and thought they were excellent and a big step up from any of the other capacitors that Cary Audio tried. Are there better capacitors? Well of course, but what will fit? My favorite of course is the V-Cap CUTF and you might find some way to fit the .22uf in somewhere on a 98L but you’ll never get the 5uf output coupling caps in there.  The Mundorf oil caps are a little bit more detailed, but some may feel could be brighter. That’s going to be very dependent on the rest of their system though. Meaning if your source or amp is very bright, overly detailed it’ll show up.

I do like the Hex-Fred’s and recommend them to give more speed, detail, imaging and improve bass speed.  I have rarely known anybody not to like them, but there are people who swear against them for technical reasons. 

Kimber Kable Will improve the sound quality, and yes it does like any good high-grade copper cable will. The problem with Kimber is there is no shield and consequently, if you’re playing another source on another input, you’ll hear it come through. Which of course you should be turning the other source off, but people will complain about that. I prefer something with a shield and recommend wires like something of a OCC quality.  
Also the Greyhill selector switch is good and provides higher quality contacts for switching inputs. It’s cheap enough that I would definitely just have it installed. 
That my two bits. 

I own a Cary SLP-98p and I fully agree with the comments from larry, russ and harpo.  Sweet, musical, but a bit "sluggish" and thick-sounding.  Nonetheless, you're wise to keep it unless you can afford something a lot better.  (I myself moved to a Don Sachs-style 6SN7 Aikido preamp of my own construction, which retains the wonderful linearity of the 6SN7 but is much faster and more transparent).  I think the upgrade would be worth it, since anything better would cost at least $3000.  I would go with the oil caps.  I don't think you'll find them dry or bright.  I use Audyn Coppers in my preamp, but unless you find someone willing to offer you a choice of output caps, you're kind of stuck with Cary's recommendation. ;-)

@dogearedaudio Which Audyn caps are you using? The Max or the regular True Copper? I used the Max caps on my Tubes4HiFi phono build and really like the sound, but the big stranded leads were a PITA to work with.

@northman - decooney, thank you. I've read some of your posts on tube rolling with the SLP 98 and they're a great help!

FYI fwiw.  My SLI-80 integrated amplifier and SLP-98L line stage had similar internal upgrades.  I've found Tube Rolling after making these prerequisite hardware upgrades is faster and more beneficial to the discovery and listening process. Sure I tried tube rolling beforehand, yet realizing the differences between tubes were much greater after the internal hardware upgrades were made first.  

A quick thank you to @decooney, @harpo75, and @dogearedaudio. I appreciate the wisdom. It helps me to think through things. I'm going to do the upgrade *and* tube rolling. Or vice versa....