I also looked at the slim models at some point, and was cooling down when I saw the specs. I wonder if Synology didn't have much commercial success with the product (?) ... judging from the amount of communication here about it, it seems it wasn't a big hit.
csimon ... you're "no compromise" ... a 4 x SSD solution would be so fast it would outperform everything else within the device (including the 1000 MB Ethernet port).
Well, the main reason I want to go for SSDs is because of no moving parts, power efficiency and no noise. Speed is a rather nice side effect!
But capacity is rather low at the moment.
But that is why I was hoping for better specs on the 409slim as the bottleneck would appear to be its processor and memory - it's amongst the lower-specced units that Synology do. SSDs are indeed the future, in my opinion, prices will come down, capacities will increase, speeds will increase to way beyond HDD speeds, but Synology only have one NAS that takes advantage of the small size of SSDs (the other units cater for 3.5" HDDs as well) yet it's the least powerful model in the catalogue.
If I've got conversion between speed units correct, here is a comparison of max read/write speeds of various Synology NAS's that I was considering, in mbps in order to compare with the bandwidth of a gigabit network, which will be 1000mbps:
DS409slim 288 368
DS209 368 584
DS410 432 920
And that's before you look at the 2011 equivalents!
In terms of home use, the DS409slim as it stands is probably more than good enough with those stats, yet you do get the feeling that these are only max speeds under ideal conditions. If you do have a gigabit network then you like to know that its bandwidth is being used to maximum effect. Also, I wouldn't want the NAS to become processor-bound, while it's indexing media files for example, so a bit more RAM and a bit more processor speed would help nicely, in line with the improvements that the other models have got for 2011. Without, as I said, having to increase the fan speed or noise or power consumption too much, if that's possible!
The slim model is indeed perhaps a bit of a niche product, it's specifically cut-down in size for SSDs (well, originally, 2.5" drives generally, but I do believe SSDs are going to be the norm in the future) so it has a limited market, maybe it was too early to launch such a thing and perhaps that's why the unit hasn't had much of a response. But now is the time!