What upgrade?

I think your amp is the weakest link in your system. Changing out the Rogue pre for the BAT pre's listed is a lateral move at best... maybe a step back. Your cdp and speakers have good reputations, so additional improvements would come at a high cost.

Suggest you sell your amp and buy a Plinius SA-102, Audio Research 100.2, or Levinson 23.5... or you can try spending less with some tweaks, such as trying some good NOS tubes ($400) for your Rogue preamp (try Brendan @ Tubeworld).

If you want to improve your CD player then you really can't look pass those Burson DIY kits. I have used them in my CDP upgrade only two weeks ago and they basically removed the digital sound from my CD player and make it sound LP like and live like.

Here's their blog that gives all sorts of upgrade tips for CDPs.

http://bursonaudioblog.blogspot.com/search/label/DIY%20Audio%20%28Tips%20and%20Tweaks%29

Well, I have not thought about if my amp is the weakest point. Maybe true, but I would rather keep it for a while. I like the Rogue preamp, but I cannot get away with this idea of BAT synergy that many BAT users talk about. That is why I am not going to sell my Rogue until I really feel the difference by myself.
I just found a Agoner who is interested in selling his vk-30 with phono and remote at my budget (well somewhat over but still within I can manage). So, I will see how Rogue preamp pars with BAT preamp. If vk-30 does not outperform Magnum 99, I would probably sell vk-200 and vk-30 and go for something like Levinson 23.5.

Burson DIY kits? Well, I am not a DIY guy, but maybe I will explore that route in the future.

Thanks.

I am not good at DIYing either but I did install their opamps which was just a matter of plug and play. There are also plenty of mod companies in the country that carries their kits and can do the mod for you. If you are dissatisfied with your CDP then I suggest moding it before investing in a new CDP. You will be surprised by the return on investment ratio compared to buying another CDP.

I once owned the BAT VK-200 paired with the VK-30. It did not a fulfilling combo for me. YMMV.

Pdreher,
I see you have Plinius SA-102 and Aesthetix Calypso. I have not heard any Calypso, but heard some Plinius int amps. They are indeed fine products.
For price wise, SA-102 and Calypso are more expensive than BAT. MSRP is $5000 vs $3000 (SA-102 vs vk-200) and $4500 vs $3500 (Aesthetix vs vk-30).
Also, SA-102 and Calypso are much newer components. I wonder how the comparison would have been if vk-250 and vk-32 were used. Well, that would not be a fair comparison either since BAT gears are 40% more expensive.
If I were to go for used SA-102 and Calypso, I would have to pay $2000 more ($3000 for BAT vk-200 and vk-30 vs $5000 for SA-102 and Calypso).

As of now, I am interested in seeing how vk-200 would match with vk-30 in comparison to Rogue. If vk-30 wins Rogue will go, and if Rogue wins vk-200 and vk-30 will go. I guess it would be rather unfair to Rogue since vk-200 has a better chance to work well with BAT preamps and Rogue may mate better with non-BAT amps.

The greatest thrill (and sometimes disappointment) in this hobby is trying new things & combinations. Enjoy the journey!

I totally agree.

The process of trying new ones is fun itself. It does not always turned into a fairy story, and sometimes ends up being a painful and costly endeavor, but it is an endless journey for many of us.