Harley has a good pverview book on the topic, but I don't know to what extent it addresses specifically what you have missed over the past 15 year.
Robert Harley's "The Complete Guide to High End Audio". The latest revision contains a new section devoted to Home Theater.
Some of your questions like, "Are combo DVD and CD players too much of a compromise over separates", are too subjective to be answered in any book, IMO. But, you might find some opinions in the threads here and in some of the on-line review magazines.
As Artmaltman indicated, Robert Harley's book would be one good resource. For even better, more up-to-date information on specific products I'd suggest you do your research right here and on Audioasylum. All advice should be taken with a grain of salt, of course, as this is (arguably) such a subjective hobby, and is chock full of folks who seem to think otherwise. Also, system/component synergy can make or break any purchase. Still, ask your questions here, search the archives (first) for answers, and I think you will be pleasantly surprised at how responsive folks will be. As you've already found with the reviews in the Audio rags, they are overwhelmingly positive, and often skewed by the fact that the advertisers are supporting the magazines. Read as much as you can, and more important, try to get out and listen with your own ears and make your own judgements. You may find that your opinions differ from the 'experts'.
Regarding your questions about universal players; some do indeed do a darn good job with all formats, though most reviews I've read indicate that the better dedicated units will still outperform in redbook (standard CD format) playback. You can read plenty of opinions here and on the Asylum as to the other formats and how they sound. I think the factor that has kept me sticking to redbook has been the lack of availability of a wide range of titles in either 'alternative' format. Right now they seem to be audiophile novelties and who knows if the recording industry will ever truly embrace either. Until then I'd rather put my money elsewhere, but that is just me of course. I'm not familiar with your front-end gear, but I'd bet if they are 15 years old you'd get a big bang for the buck in replacing your DAC/player combo.
As far as further advice, you may do well by stating some of your own listening preferences as systems may be put together to suit those.
Above all, enjoy the music!
Thank you all for your responses. I have been on this Audiogon site for about 2 weeks and am finding it filled with the nicest and brightest folks - what a pleasure!
I will get Harleys book.
I like to listen to Rock, Classical, New Age - often love a solo instrument or voice underproduced and filled with heart. Particularly piano. I play a 6'8'' Kawai Grand. I dont think I want to get into tubes - any suggestions for new or used 3K or less each, a great CD transport or player and speakers for a 38' by 22 live room? I love the detail one hears with good headphones.
Gammajo- Given your musical preferences, large room, your love of the piano, as well as your appreciation of the micro-details available through good headphones and head-amp, I'd say you're just fine sticking with SS amps. I'm not sure why, but they (SS amps) do seem to do better justice to the piano in my experience, than tubes do. It is the one instrument I consistently prefer hearing with great SS gear, otherwise I much prefer tubes for most of the music I prefer.
There are plenty of great standalone players and player/DAC combinations in the $3k range. If I were looking in that range I'd be considering the offerings by Muse, Electrocompaniet, Ayre, and Resolution Audio. My experience with players of this caliber in particular, is that you'd be splitting hairs to make a decision among front-ends like these. The best thing to do is to go and hear a few for yourself in order to find your own preference. Each may have different strengths, while none will likely have any significant weaknesses. Do searches on each, and on any other suggestions you may get to see what folks are saying about them. You may even find a few direct comparisons. I've stuck to my Muse rig which is pretty dated at this point, yet continues to sound wonderful to me. It occurs to me as a very neutral, uncolored sound with a huge soundstage and plenty of detail. I've enjoyed hearing the Electrocompaniet, but never heard the two side by side. Many great things written here and on the Asylum about the Ayre and the RA, and my friend who has never steered me wrong has been going on about his RA Opus like it was God's gift to redbook. So there are four suggestions to start with, and you will no doubt get plenty more.
Outside of Robert Harley's book, you might want to look for a book by Laura Dearborn's book entitled "Good Sound: AN UNCOMPLICATED GUIDE TO CHOOSING AND USING AUDIO EQUIPMENT". Both books are good and cover much of the same material, but their writing styles are slightly different. As such, you might connect with one writer better than the other, making it easier to absorb some of the information provided. Sean