I have a SP-1, and am extremely pleased with it. I bought the SP-1 because my primary objective was to get excellent 2-channel audio reproduction while also getting high quality surround sound processing. Bryston's SP-1 delivers on all counts.
If you access the Bryston home page (www.bryston.ca) and read the reviews of the SP-1, you will read many of the comments I would make if writing a lengthy review. The SP-1's analog circuits are open, transparent, detailed without being etched, with excellent transients and dynamic response, precise and realistic imaging, and CLEAN CLEAN CLEAN -- damn but the sound is clean! The audio quality is neither "tubey" nor "transistory" -- just very natural and balanced from top to bottom. The surround sound processing is also first-rate -- the best I have heard from any unit under $5000.
(You can read about the system that accompanies my SP-1 by looking in the "virtual systems" section under my user name Sdcampbell. You may also want to look at the reviews of the SP-1 on "AudioReview".)
The SP-1, as Bryston states on their Web site, was designed for audiophiles, and it lacks some of the features that some HT buffs may want, such as video switching (which degrades the audio quality). It also lacks 5.1 SACD and DVD-A inputs, but the SP-1 has a modular design, and was specifically built to allow for future upgradability. According to James Tanner at Bryston, SACD and DVD-A audio inputs and circuitry will be offered in the near future as an upgrade modification.
The SP-1 is easy to program, even though it has no on-screen guide (no video switching, remember). I was able to fully program my unit in about 20 minutes, after I finished reading the user's manual.
The DSP for music is, as these things go, pretty good, although I rarely use the DSP effects. Of much more importance to me is the analog bypass circuitry, which uses the same circuits found in Bryston's top-of-the-line BP-25 preamp. I particularly wanted an analog bypass, so I could play my LP's without having the analog stream go through digital processing. Be aware, however, that there is no built-in phono preamp stage -- I use a Lehmann Audio Black Cube SE, which feeds into one of the line stage inputs. The SP-1 also offers balanced outputs, which is very nice if you have an amp with balanced inputs.
The remote is made from a heavy billet of aluminum, and features automatic back lighting when the remote is moved. The remote operates most of the needed functions, but lacks a few, such as a "bypass" button. To engage the analog bypass circuit, you must manually push the button on the front panel of the SP-1.
The bottom line on this unit, however, is the excellent audio quality, rather than the features (although it has most of the features you will probably want). By any objective standard, this is a high-end audio preamp. I recommend the unit very highly to anyone whose first priority is a a top-notch analog and digital preamp, but who also wants an excellent surround sound processor as well.
