Never really used ULV cpu and never looked into them. Are they much slower than regular CPUs?
I just don't want the viewing angles I had on the thinkpad edge. They were terrible, I had to have the screen positioned just right to have an acceptable view. The TN panels on the m4600 look 20x better.
It depends on what you are doing and what your expectations are. If your current computing is the machines in your sig though than the ULVs will still be an upgrade.
The main difference is 4c/8t(4cores/8threads) availability vs. 2c/4t only for the ULVs. So there will be a huge gap in workloads which can take advantage of those extra cores (eg. encoding and rendering). The full mobiles also are generally clocked higher and also cocked higher for the GPU. The trade off is the ULVs use much less power so you do get the benefit of more battery life and/or size weight savings on the battery as well as cooling (overall better size/weight on the laptop).
The other benefit here, like mentioned above, is it opens up a lot more choices with IPS displays, especially if you want less size/weight as well.
Are you sure the m4600 was a TN panel though? It does come in a IPS variant. The 1080p models are IPS I believe.
If you are otherwise happy with the Thinkpad brand there is the 14 inch Thinkpad T series now with 1080p (or higher) IPS displays. There are two variants, one with a full mobile CPU and a thin/light ULV model, both with 1080p 14 inch IPS displays. MiniDP to HDMI is a simple adapter that costs a few dollars. I'm not sure about mSATA though, you'd likely need to confirm with Lenovo. Although I believe the T440S is M.2, which is a small drive factor similar to mSATA but not compatible, so that isn't useful if you have an existing mSATA SSD.
This latter requirement also adds a bit more restrictions. The y410p and Macs are not mSATA either.
What do you want to upgrade by the way? Ultrabooks are somewhat more limited in that area as ram might be soldered onto the board with no actual slots.
