Obviously, the best thing to do is to demo them yourself, however, I will discuss what I know of two of the ones you mentioned.
I have the Ayre K-1XE preamp, and it is the cornerstone of my system. (I doubt I will be upgrading beyond it to be honest.)
This preamp is very neutral, has great transparency, and has good frequency extension. It has a very musical sound, that I normally would not associate with solid state. It is not warm per se, but it really does not sound solid state either, IMHO anyway. (Note: I would not consider this to be a warm sounding preamp however. If you desire that, I suggest a tube preamp, like a ARC Ref. series, a Hovland, or a CAT Ultimate.) It has 6 inputs, 3 SE and 3 XLR. It is a fully balanced design. I like having so many inputs, as I use a CD, CD-R, SACD, Turntable and a tuner. (Damn, I need one more balanced component to fill 'er up!!) The build quality is excellent. (And while it does not matter to the sound quality, I like the aesthetics of the unit too.)
It has the (optional) remote control. (Note: not all of the top end preamps have a remote option, and I really like having a remote, since I use a analog source mostly), although it does only control the volume and muting).
It also has (optional) phono boards that are very good. This makes the phono stage about as good as you can get in a full function preamp. It has the deep dark background that I really like. You can get a better phono stage, if you are willing to spend big time cash for something like a Manley Steelhead or a Basis ASR Exclusive. (I will point out that the phono stage uses the XLR inputs, like the Basis ASR does. So you will likely either need to use adapters or have your tonearm wire reterminated.)
I did demo the Mark Levinson 380S, and it was good preamp, but I prefer my Ayre, as it seemed, to me at least, a little less solid state sounding. It seemed a little analytical to me. (However, if you already have a warm sounding system, this might not be a concern.) I was running an all solid state system at the time, and I did not want too much of the solid state sound. The build quality is top notch.
I know nothing about the McIntosh.
Hope this helps.
Good Luck in your search.
I have the Ayre K-1XE preamp, and it is the cornerstone of my system. (I doubt I will be upgrading beyond it to be honest.)
This preamp is very neutral, has great transparency, and has good frequency extension. It has a very musical sound, that I normally would not associate with solid state. It is not warm per se, but it really does not sound solid state either, IMHO anyway. (Note: I would not consider this to be a warm sounding preamp however. If you desire that, I suggest a tube preamp, like a ARC Ref. series, a Hovland, or a CAT Ultimate.) It has 6 inputs, 3 SE and 3 XLR. It is a fully balanced design. I like having so many inputs, as I use a CD, CD-R, SACD, Turntable and a tuner. (Damn, I need one more balanced component to fill 'er up!!) The build quality is excellent. (And while it does not matter to the sound quality, I like the aesthetics of the unit too.)
It has the (optional) remote control. (Note: not all of the top end preamps have a remote option, and I really like having a remote, since I use a analog source mostly), although it does only control the volume and muting).
It also has (optional) phono boards that are very good. This makes the phono stage about as good as you can get in a full function preamp. It has the deep dark background that I really like. You can get a better phono stage, if you are willing to spend big time cash for something like a Manley Steelhead or a Basis ASR Exclusive. (I will point out that the phono stage uses the XLR inputs, like the Basis ASR does. So you will likely either need to use adapters or have your tonearm wire reterminated.)
I did demo the Mark Levinson 380S, and it was good preamp, but I prefer my Ayre, as it seemed, to me at least, a little less solid state sounding. It seemed a little analytical to me. (However, if you already have a warm sounding system, this might not be a concern.) I was running an all solid state system at the time, and I did not want too much of the solid state sound. The build quality is top notch.
I know nothing about the McIntosh.
Hope this helps.
Good Luck in your search.