Quad ESL 63's-Can they play rock music?

A business accquaintance I deal with approached me today completely by surprise and mentioned he had a pair of Quad 63 ESL's that he wanted to sell me for $200!
I took a walk to the back of his office and sure enough there they were.
He mentioned to me that the speakers needed repaired at a cost of $600 from what Quad told him and he already purchased another set of speakers.
It would be my responsibilty to box, ship and deal directly with Quad.
A few things...
I guess first of all, is this a good deal?
Secondly, I do listen to a lot of different music, but I certainly enjoy my rock music and I'm concerned about the lack of a bottom end that these speakers are rumored(?) to have as one of their traits.
This is the speaker that got me involved in this crazy hobby as a teenager and I've always had a desire to own a pair...but are they the right speaker for me?
Your thoughts please.
Cary 303/Rogue 66 Magnum/Odyssey Stratos

Thank You!
Yes, it's a good deal. They can play any kind of music you want to play, but not very loud. The midrange is awesome. It's not the type of speaker I'd want to play AC/DC on, but it will do it. Just not real loud. They are not a pro sound reinforcement speaker for concerts. They are a stately and proper ESL for fine musical reproduction in your parlor.
I second TWL's comments. I love the Quads and, over time, have owned 2 different sets of USA monitors, but I spent a lot of money replacing panels on both sets. The first set came from Florida, so I thought the panels were more prone to arcing due to their use in a humid environment. The second pair was new and still had panel problems. I used a VT100 and VT100MKII and, on occasion, would try to play at moderate levels in a small listening room. Although I did not consider that I played them loud, my dealer and the importer judged that the panels were likely damaged by playing them too loud. So, as much I like these speakers, they were very frustrating and expensive to use and maintain. I ended up selling them.
Of course the Quads will play rock, but the fact is they are not optimized for loud playback (> 85dB). They will give solid and very tuneful bass response down to slightly below 50Hz. The extreme high end is a little rolled off, but the mid-range is still state of the art. I am not familiar with your power amp, so I can't say if you could just drop the Quads successfully into your system, but I would still strongly advise your to get the Quads, if only as an experiment. Used Quads in decent condition can be sold for $1,400 and up.
I've owned two different pairs of QUAD 63's and a pair of QUAD 57's and I loved all three sets , and played a lot of rock on all of them. After all, even AC/DC has a midrange.
Actually very little rock has bass below 50Hz and the QUAD's are surprisingly good in the midbass region. QUAD's really are everything everyone says about them. You'll never regret owning a pair, even if you don't keep them. By the way, don't toe them in and do drag them out well into the room. Peter Walker's rule of thirds really works (1/3 of room length, 1/3 of room width). But, eventually, domestic unacceptability of correct placement will make you sell them. Until then you'll have a great listening experience.
I second ALL of the above. As you described them, these Quads are indeed a bargain.
You'll find solutions for whatever is needed -- and, as Seth notes, even AC/DC have midrange.
I have owned 63s, have had them modified by crosby and had occaisionally replaced panels. That being said, I have kept them for almost 20 years. Although they have some limitations, I have never heard anything that matches them. I both listen to rock music and play electric guitar. Although the quads won't play shatteringly loud they are certainly reasonably loud. If you need louder get a powered sub and use a high pass cross over. The quads will play louder and you will get added bass. Nothing I have ever heard produces sound across the range as naturally as the Quad. It sounds like a steal to me.
Many thanks for your feedback