Prior to taking delivery of the SL500, my experience with modern thinkpads was limited to a T500 - otherwise I have been using A31p's and 770x's for years.
My impression of the SL500 is very favorable so far and I would summarize as follows:
1) Excellent value - was able to build a machine for under $525 (before taxes, fees) including a T6570 Core 2 Duo, wireless N, bluetooth, Camera as upgrades over the stock (1GB ram, 160GB 5400rpm, DVD writer, Vista home basic), AND including a 1680x1050 matte screen. I don't where to buy a $500ish notebook from any other vendor with a High Res Screen, matte or otherwise.
2) Very good build quality - no flex - don't know what people are talking about when they say it's of poor build quality. Actually the T500 feels a bit suspect to me to be honest. Now the T500 is packing more into a much smaller package.
3) Very cool running, perhaps not having a discrete video card helps, but it's the coolest notebook I have used including the T500.
4) It's big by todays standards no doubt, but it's smaller than an A31p/770X brick (yes, I know those are old and ancient machines). Despite the SL500 being big, it has a very nice and agreeable weight distribution - it feels balanced and I think there is something to be said for that.
5) Battery life is sub-par for a 6 Cell LION battery - about 2 hours at max brightness and running on Desktop profile and High performance. That is how I generally run, so what that means is that a T500 would be better, but how much better, perhaps another 30 to 40 minutes?
6) HDMI built in. Display Port sans audio support (as with the current T series) is a misstep to say the least. No way Lenovo should have adopted Display Port until one could at least use an HDMI adapter with full support (i.e. including audio). So, if I understand things correctly, the SL series may be the only Thinkpad available with a fully functional HDMI port.
7) Glossy top of the laptop is lame just because it shows and seems to grab fingerprints, etc.
9) Personally I would like a built in smart card reader or at least the option to add it like the T series.
10) Oops almost left this out - keyboard and trackpoint are excellent - trackpad seems fine but I don't like them so I don't care about it anyways.
11) The screen is acceptably bright, but I would like it a bit brighter. The T500 has the same resolution screen but it's generally "docked" (plugged into an external screen), so I can't say if it's the same panel as the SL500 or not or therefore whether it's the same quality, better, or worse. One more note on the T500 - it's driving the external monitor via the VGA port (because I have not yet purchased a Display Port to HDMI or DP to DVI adapter or cable, etc.). The quality of the VGA output seem low on the T500 - or maybe it's the external Samsung monitor, I don't know - both the monitor and T500 are new. However, when I drive the monitor via HDMI from the SL500 it looks perfect.
Conclusions:
The consensus bashing of this series on this forum is misguided at best, and is missing a key point I believe. As a long time Thinkpad user, I have for years wanted access to it's core features at a lower cost. In fact most thinkpads I have owned have been purchased as used machine - often several years behind.
Lenovo should build on this Series. One question I have is how profitable is this series versus the other series - I would suspect and be somewhat concerned that they aren't all that profitable at the price points they have been available at in the recent past?





