What's Your Advice, Used Audio Research LS15, Or Freya+?


Title says it all. The LS15 I'm looking at is the older model without detachable power cord. I'm looking to dabble in a tube preamp. I'm running a Bryston 4bSST for power.
128x128zerobias
Thanks to all for their thoughts. One more question. I am looking at two very nice LS15's. The first is an older model with the attached power cord. The second one is a very late model with the detachable power cord and various ARC improvements. The price difference is $600. Is there $600 dollars worth of performance difference between the two? 
@zerobias the new modal with detachable cord has Infini Caps which where a upgrade to the REL cap in the older modal. If yo sent the older modal out to ARC for a cap upgrade it would cost about $600. I have had my LS15 for 16 years and am the second owner with no problems at all, works perfect and sound great.
Just want to thank all who responded, here and by PM. The input is greatly appreciated. I found and purchased a very late model LS15 with all of the upgraded caps, the power supply, and the detachable power cord. Looks very nice from the pictures. I hope to have it Friday. Now for a headphone amp, it does not have a headphone jack. Thanks again, and happy listening.
Good choice zerobias. Once you get it start thinking about new tube and get a good PC to bring out the best sound. If you need a headphone  amp I like the Drop/Cavelli CTH amp. It goes for $175 on Drop.com and I love mine using with Grado SR325i and HIFIman HE4xx from Drop.