How do the Magnepan 1.7's sound

Laterglas, I would agree with you. Just using logical thinking, the possibility of Manepan putting out a speaker that marginally surpasses a 10-year old model is highly unlikely.
What is more likely is that the speaker had good days and bad days, as is common at shows.
I worked with Jonathan Valin at Fi and know how his mind works. If he says the bass choirs remind him of the Magnepan 1-U in clarity and that was his benchmark of bass realism, to this day, then he was either high or correct. I vote for the latter. Manepan has never been the kind of company to put out incremental improvements: the adjustments are usually extremely significant. However, the electricity of any room at CES is suspect, depending on the time of day.
I trust Jonathan's assessment. The only caveat is that he likes smaller scale music and vocals, not symphonies (it would be nice if TAS used musical examples, complete with the version, as they once did) so that one could hear what they heard (system variances withstanding).
I find it exciting that a speaker can be good from 35 to around 300hz, where so much power lies. If the upper midrange is equally open, this should be a killer speaker!

Here is a link to a longer review from Jonathan Valin of "The Absolute Sound".

Magnepan 1.7 review

The 1.7s are now mine! Muhahaha
Just got back from a 10 hour roadtrip to pick them up, still tweaking the final position, but they sound utterly fantastic!

front of the "chamber":
http://s142.photobucket.com/albums/r117/dawsonblah/?action=view¤t=front.jpg

back of the room:
http://s142.photobucket.com/albums/r117/dawsonblah/?action=view¤t=rear.jpg

I have been living with my MG 1.7s now for two months. Shortly after purchasing the MG 1.7s, I purchased the Wyred for Sound DAC 1, a Netgear 9150 digital music center and a Polk Audio DSW MicroPRO 2000 subwoofer so some of the subjective changes in sound quality can't be pinned on any one piece of equipment. Other equipment includes a BADA MA3MK II tube hybrid preamp and MA100MK II amplifier (300 watts into 4 ohms). All wiring is Xindak ribbon speaker wire and Xindak analogue and digital cables.

The past two months have been an amazing journey with the new equipment. I replaced 5 year old MG 1.6s with the MG 1.7s (along with an original 35 year old pair of MG IIs!). As the equipment has broken in the clarity of sound is becoming nothing short of outstanding. The combo, Magnepan and Wyred 4 Sound DAC, has been a marriage made in heaven. Both seem to provide amazing clarity without sounding etched or unrealistic. I primarily listen to classical music and couldn’t be happier about the sound quality. Music ebbs and flows and where orchestra crescendos used to send me to the volume control to turn it down, now explode with amazing control. It really is phenomenal.

I have always had a problem getting “depth” from my system. Clarity, realistic reproduction of orchestral instruments and vocals have been outstanding but all were presented within a broad right to left very narrow depth presentation. For the first time, I am getting some depth to the music. Still not what has been reported by others with Magnepans, but much better than ever before. I am still tweaking the position of the speakers to try to improve the depth but it is a work in progress.

Rock music, for the first time ever for me, sounds good through Magnepans. Always to me a weak link, I now enjoy listening to rock music through my system.

I will be visiting a gentleman who has a dedicated sound room with MBL speakers and amplifiers with analogue front end on June 19, 2010. I estimate he has between $50K and $100K into his system. I am very excited to hear what the absolute top end sound equipment can bring and to be able to compare it to my system which is based on the “best deal for the dollar” strategy. If we can work it out, I may bring my Magnepan 1.7s to his system at a later date to hear what a top end turntable and MBL amp/preamp can do with my speakers. Will follow up on this later.

For now, I am very happy with the quality of my system. The weakest link is likely the small Polk subwoofer; however, I must say it is amazingly good for the price I paid for it ($429.00 at Newegg with list over $1K) and very convenient with a separate remote control.

these sounded very good for classical and jazz.

haven't heard them with pop/rock yet