D.I.L.E. I own a CAT SL1 Sig. This is the first preamp that Ken Stevens starting using the current heavy duty chassis with. I have rolled in tubes into my unit which I think has helped enormously. IMHO, this preamp is still VERY competitive with the best I have heard. If you can get a chance to listen, then i would suggest that you take that opportunity. I do ask that you inquire of the Seller as to how old the tubes are in the unit and if they have been changed out, what is currently being used. ( The choice of tubes can greatly change the character of the SL1, like most preamps that is sometimes NOT for the better). Another thing to consider, what amp you will be using with the preamp you will ultimately end up with? While the CAT works well with most amps in my experience, it's always possible that a mis-match could occur. So, if you like the sound of the pairing at your dealer, make note of that and ask the dealer what else he might suggest to give you the sound you like. Remember the GH's are ultra revealing, so a good quality amp is a must.
I think Lloydlee summed up what else to consider when listening to a preamp. One other thing, which sounds a little obvious but perhaps isn't: The preamp is the 'control center' of your system... You may want to make sure that it can control and hook-up to all the other gear that you plan on using..now and possibly in the near future. As an example of this, the CAT does not have a mono switch, so if you want to listen to a lot of mono LP's, this might be an issue. The CAT is also a single ended device that does not have the ability to output a balanced signal...some people want a balanced connection or require a balanced connection for their amp...again, IMHO, the CAT probably isn't for them. If you are planning a major home theater system, the CAT probably isn't going to do the job.
One other thing, I still think you may want to look at your source component first, before delving too much further into the amp/preamp changes.
