Given the i3 intel NUC is now selling for $260 that may change this comparison markedly
http://www.amazon.com/Intel-Computing-Gigabit-i3-3217U-DC3217IYE/dp/B0093LINVK
To me the mainboard flexibility of AM1, that it's supported in a variety of boards to plug in to existing cases and power supplies, is a major advantage. intel NUC don't actually go into low power mode without the latest power supply anyway and some mainboards simply do not support this Haswell mode. ASrock alone has three AM1 boards
http://www.asrock.com/news/index.asp?ID=2039
I think anyone choosing the AM1 architecture is going to probably max the CPU regardless of the extra $20 just to avoid the bother and risk of changing it after the mainboard is out of warranty. So the solder vs. not just isn't a factor. You don't build low end PCs like this to volunteer to open them up later. You will be giving them away to your elderly relatives, putting them in the guest bedroom, etc..
I don't find either the intel NUC nor the AM1 systems appealing yet for a couple of simple reasons:
1. Just one Ethernet port. If you want to keep the desktop or HTPC silent and small, then you must keep the spinning storage drives far away over the gigabit switch. If you want the really big 1080p files to stream perfectly you may want them on the HTPC. But with just one port the HTPC is a poor NAS so you will end up with media drives attached to the HTPC and other drives attached to a NAS... maybe better for reliability (a flood, fire or jerky cat could decide to take out one set of drives) but not for simplicity. I want one two-gigabit-Ethernet machine near my big TV and another near my desk. I want them connected directly to each other and each to a switch and/or NAS. I want file systems that can handle multiple continuous >100mbit/second loads. So far the only OS that can really do this is FreeBSD/PC-BSD. Fine. I can run Linux at the desktop, Windows at the TV, and BSD on the NAS... but I want one hardware solution and two one-gigabit paths to each drive on each machine at full load.
2. No Thunderbolt yet. I would rather have 10 gigabit powered copper Ethernet get very cheap very fast, just as Firewire made gigabit Ethernet cheap, but until then the 20gbps 100-watt 2x2160p Thunderbolt cable is going to rule big multiple displays. Seriously, 1440p is now under $400 if you look and wait, 2160p ("4K") is under $600. At least *three* not two monitors are required for wraparound gaming, and three 1080p monitors will set you back a whopping $300 if you buy used... so why in the world do I want just two displays? Three is the minimum regardless of the resolutions and at present Thunderbolt is the only connector that is going to do that for me by display chaining.
2a. Three HDMI 1.4a connectors is a fair substitute, though they still require monitor power connectors and therefore are going to be far less efficient than chaining monitors with Thunderbolt, in both cable and power terms. So far the low end systems do not seem to have triple monitor support.
3. Uncertainty about the flash RAM interface. SATA6gbps SSDs just seem like a bad solution as they add a bottleneck and can only be managed as single drives - for RAID0 you need two drives. PCIe SSDs fit in those unused x4 PCIe slots and can be managed better, as multiple drives usually, supporting up to RAID6 on a single device, or splitting in half to accelerate you to RAID0 type speed. RAID0 is a 800mph go-kart anyway so if you aren't backing up this boot image on spinning metal every week, and keeping your data elsewhere, you're a fool - best to keep such images small and local to what the machine is doing, and to keep all the user data in a vault say off on the NAS far from jerky cats.
Now there are Ultra-DIMMs which seem high end but so did PCIe SSDs a few years ago.
I would like to see AMD announce whether there will be an HTX3.1 direct interface for Ultra-DIMMs etc. or whether they see the PCIe slot as being the way for big flash arrays to be connected to the CPU. I think with their deals with OCZ they are signaling the latter.
4. Other port and connector issues. The whole thing seems uncertain right now.
Thunderbolt, USB3, SATA6gbps, mSATA, mini-PCIe, PCIe... there are getting to be competing standards for how to hook up a lot of flash ROM inside or outside the box. I find this very disturbing. I was glad when eSATA died since it never worked. Glad when Firewire died because USB3 and gigabit Ethernet ate its lunch. I will be glad when some of these other connectors die in favor of say GIGABIT POWERED ETHERNET which works now and does everything in VoIP and security. And TEN GIGABIT POWERED ETHERNET which could remove the need for Thunderbolt up to 1440p...
5. Apple hasn't moved yet. Due to its unthinking fanbois and fangrrls, Apple can create an overnight lead market just by announcing the specs of the latest Mac Mini. If it's say an i7 based intel NUC with two Thunderbolt connectors and two gigabit Ethernet connectors (one powered) and two USB3 ports, and a PCIe slot useful for a 10 gigabit Ethernet or PCIe SSD or fiber optic interface, that will tell us a lot. Mainly that Apple is smart. Or it could be the same thing but based on a new AMD socket simultaneously announced, putting AMD boards seriously into the Thunderbolt market also, and giving Apple two viable Thunderbolt optimized CPU suppliers to choose from (what I would do).
If Apple was brilliant of course they would release both an AM1 based low end Mac Mini refresh that can handle 3x 1080p and a high end brand new intel NUC they can have exclusive for say two years that can handle 3x 1440p or 1x2160p+2x1080p displays. And an Apple branded NAS. All at typical Apple inflated price points, but loaded with goodies like
- PCIe SSD configured for RAID0 with automatic image backup and restore from network storage or the cloud. RAID6 for the NAS running a stripped down MacOS/X which is actually really just BSD...
- excellent pricing for the 2160p "4K" display and 1440p "iMac/Cinema" displays refreshed with actual VESA mount points for multi-monitor arrays (right now you have to buy absurd adapters)
- bundling with a new iPhone the size of a Samsung Note, and an Apple iWatch, giving you the walk-around and sit-down experiences you actually need, and eliminating the need for tablets, laptops and making the wait for AR glasses/ Google Glass a lot more annoying as you will not need anything new until then.