Pioneer P80RS, Alpine 9887, Clarion 786.
I've had my very good fortune of hearing these HUs! :
Without any experience with the X991 I would rate the HUs below.
Clarion 786:
I'd select this one as the winner of the trio here. A very good sounding, feature packed and most attractively priced unit. It sounds much refined for it's price. Has all the necessary features (& some more) one would wish in an advanced HU of these times, and has a very great price tag which blows the competition off. Well! The interface and appearance may not gel with everybody though.
Alpine 9887:
This HU takes the 2nd spot according to my ears. A famous ICE enthusiasts' favourite currently. True to the brand sound, decent features, trademark but bettered interface and distinguishedly Alpine appearance. It sounds like a typical Alpine (some love it and some hate it). Has some of the very good audio and interface features but falls a bit short on connectivity options. Interface is typical alpine but in this version, they have smoothed out some rough edges in the navigation and controls. Once you look at it, you'll know it's an Alpine. Very classy, trademark appearance.
The extra emphasize on the upper mid ranges as mentioned by some here do exist in many Alpine HUs. And this can be a bit too irritating if one listens to music for long periods on a mid strong speaker setup. I think the imprint kit may solve this issue to an extend but it is a drawback in this otherwise a masterpiece of a HU.
Pioneer P80RS:
I don't like this HU. My first experience with this one was not very deep and I liked it initially. The second experience was in one of my close friend's car. I was the one who recommended and bought the HU for him. Initially, I was impressed but it wore off soon. As I paid close attention in some weeks, I didn't like the sound. There were many things lacking in my kinda music. Bass sounded a bit too emphasized and sharp also. I blamed it on the speakers and reasoned myself. But I changed the speakers and nope! It didn't make much of a difference. I re installed the whole setup spending more than a week behind it. Umm umm!! It didn't raise upto what I want. It appeared to me as a glorified version of the 8850 which was available at that time (early 2007). I changed the HU to a famous Alpine of that time and voila!! The whole setup came alive. 1.2lacs spent on the setup now stood up in pride! I was happy.
There on, I haven't given this HU any good place in my heart or mind. I did listen to a few setups later on where this HU was used and sounded good, but I never felt it to be rated in the distinguished status of a High end HU. I did like this HU in Flying bong's setup, Amey's setup and B&T's setup. All have different speakers, amps and cars. But as I said, I always came back with the feeling that it could've been a bit more better if another HU was on the lead. Many experts here (Gunbir, B&T and FB) have used this HU in their own installs and have said good things about it. So, is it just me? Hmmm... Once bitten....
This is straight from my mind (what I've experienced) and I never once held back my fingers while typing this.
Regarding Kenwood, they're making some very good sounding HUs lately. Their entry level (basically made by Nippon at some chinese factory or so..) did bring a lot of bad name to this brand. But their higher end HUs are simply a class apart. Their reference unit KCD01 is one of the best HUs I've ever heard in my whole life. Even their mid level HUs are warm sounding and very natural.
I'm yet to listen in detail to any HU above 6539 and some 7xxx HU my cousin has in his car in Dubai. 6539 is one amazing HU with the best sound in it's price range. Even the 7xxx is one amazingly great and natural sounding unit. I've randomly listened to many Kenwoods in ICE showrooms and electronic stores in my nomad kinda life. I did like many of them and always wished to buy some high end stuff from them. X991 is a worthy contender it seems! I'll be able to tell you about it after my next trip to Dubai. Lol!
@Frank, devarshi...
There're quiet a few differences in the 785 and 786 models. Check the specs carefully before you sink in!