Mcintosh mx136 vs Mcintosh Mx150

Did someone had experience with both of those preamps?
Which one has better sound?
  I've owned an MX 134 for about 12 years now, and have loved every minute of it.  I'm curious too if the newer models sound that much better.  I demoed the MX 121 and 160 in Magnolia Best buy, but they were just playing movies.  The dialogue was very clear, but not that much better/different than what I have.   I'm sure Room Perfect/audessey could help with bass, but the mids/highs, just didn't floor me with better sound as I was hoping.    I think it's a testament to how good the 10 to 15 year old Mac stuff sounds.   I really didn't hear anything better that would make me want to spend $4,000+  to get a 121, or 6,000+ to get a 150/151.   Keep in mind I'm 80% music/20% movies, and really don't care about surround sound. 
Is what i belive but i need more toughs from other people too before to get a Mx150.

I am not a 100% sure, but I believe the MX136 was that last Pre-pro to have a true analog in analog out circuit path. My understanding is the MX150 runs everything thru the digital processing to the outputs. I guess the thought is to have all signals available to process for room correction. You might give McIntosh or the guys at Audio Classics a call to confirm.
i had owned a number of Pre-pros from C39 thru MX135, then changed over to a D2v Anthem Statement. I miss the analog pass thru for the 6 Channel. 
As far as making comparisons, I have heard and watched both 136 & 150 but not in a manner to make comparisons. One thing to be concerned with as the MX136 is pretty old in "digital years" so the HDMI , MAY NOT have what you need if intermixing today's video products, but I don't know on that.
Thank you. From i know the true analog sound lot better compare with digital sound, to my opinion.