The Nak LX-5 is my fav all time deck to record with. I have a Nak 600 also, and I like it because of its time and place in the history of cassette technology AND it's build is SO SOLID for it's day. Similar to my Tandberg upright, 310 MKII, which is also a wonderfully over engineered piece for it's day. Still, both decks sound warm and spacious like a good Nak/Tandberg deck should.
Recently, I've added a Tandberg 3014 and am still struggling with the meter adjustment (needed new coils and had them professionally replaced) and the sound, even in nearly dialed in condition, is unbelievable! Today, I'm picking up my most recent purchase, a Luxman LX-102. I've heard these decks (like the K-05) will kill and out-perform many digital formats.
My system is built around a Quad receiver, and NOTHING sounds as good as straight vinyl on my system. And with a great classic cassette deck, I just can't imagine EVER being without my analog heavy, wide open soundstage...
Great topic!
Analog rules!