CAT SL-1 vs. ARC SP-10

Want to upgrade from my ARC SP-6C1 to one of these two units. Anybody owned both these before? Would like the plus and minus of each.
I have not woned both, but I do have a CAT right now. The only real issue you should be aware of is that the stepped attenuator, coupled with high overall gain makes for some issues. I have gone to using the Rothwell fixed 10dB attenuators to control. Otherwise, 9 o'clock is loud (10 is deafening) with relatively inefficient Vandersteens.
I currently own the SL-1 Mk 1 with some upgraded (from CAT) parts to the power supply. It does not have stepped attenuation as does Swampwalker's and the SP-10. I have a friend that has the SP-10 Mk2 and have listened to it extensively several different times in my system. I have also heard the CAT extensively in his system so there are certain characteristic differences between the 2 units that are notable.

First the SP-10 has such a lovely deep and richly layered midrange that it is just hard to find fault with it in that area. The CAT would be categorized as more neutral in this area. Some may say cool but not I. It just seems to reflect better the recording than the 10 which makes everything sound great and this is not a bad thing, highly listenable.

The big difference between the 2 pre-amps is at the frequency extremes where I feel the CAT is better at both ends, better definition and control in the bass, the 10 is a bit fatter by comparison and more extended in the highs.

Which one is better? I wouldn't even attempt to say since each have their own virtues and only you can judge in your system. I could live happily with either.
Thanks for the input. I agree w/ Tubegroover that in the end I'll have to trust my ears. It is nice to know the differences between the preamps especially in the SAME system (cable interfaces aside)...this is what I was hoping to get as a reply.
Thanks Swampwalker for the issue on the stepped attenuator...I have a similar issue with my ARC and various amps where 10 o'clock can be louder than I want.
On the issue of gain, the SP10 has a gain reduction switch on the face of the preamp which allows you reduce the gain of any incoming signal by 12db - this gives you quite a bit more operating room with the main volume control.