Read Jim Schulman's superb review. It's pointless for an amateur such as myself to attempt (and fail) to repeat his expert analysis.
The upshot is as follows:
This machine combines high quality internals with a cheap (but durable) body. This was a compromise that I, wishing to keep the costs down, found perfectly acceptable. It makes very nice espresso and has excellent steam capacity for milk drinks. Starshmucks can't touch it (not because they have inferior machines, but because I use better coffee).
Negative Product Points
The brewing indicator light went dead a while back, and Baratza seems to have ignored my emailed request for a new one. This doesn't matter much in practice, because it's quite easy to surf by listening for the telltale click of the thermostat or relay that ends the heating cycle. I guess I'll try calling them next.
(Update: Baratza came through with the wiring harness under warranty).
There is some flex in the body of the machine as the PF is tightened. Although this was midly alarming at first - I wondered if this was stressing the "plumbing" connections - after I took a look inside it became apparent that the internals were completely isolated from any ill effects of the flex.
The machine comes with restrictor and pod baskets only. Maybe this is good for the great unwashed who use 3-month-old pre-ground, but aftermarket non-restrictor baskets are essential for getting the most out of fresh beans. I have tried the restrictor baskets just for grins, and the result is plain tasting stuff with weak crema. Fortunately, the good baskets are quite available everywhere on the net.
Detailed Commentary
I took a peek inside the machine to evaluate the indicator light situation, and the internals looked quite solidly made and laid out with care. I suspect I can swap out components (e.g. replace the pump) by myself. (This can't be more complicated than rebuilding a 16 valve engine :-)
We've been using the machine for over a year, pulling about 5 doubles per day on average. With the exception of the light, which is basically irrelevant to the primary mechanism of the machine, it has been rock solid. With fresh beans, an MDF, and non-restrictor baskets, the SL-70 makes excellent americanos for me and macchiatos for the wife.
The machine is plain-looking. Those wishing to impress their conspicuously consuming peers should look elsewhere, but I suspect this inference is already built into the price tag.
For $300, it is superb. The reason I answered "no" to the question of whether I'd buy one again is twofold. First, it's not clear that this thing will ever die. Second, I'd like to get more serious about my addiction and move to a double boiler machine with a commercial group.
Would I recommend this machine to those not wishing to spend a small fortune? Most definitely.
-------------- 2-Year update follows -----------
Baratza came through with a replacement indicator light harness, which took about 5 mins to swap into the machine. Since then the machine has been trouble-free. Of late I've been using reverse osmosis filtered water, which seems to work very nicely for keeping calcification under control, so this machine might be long-lived indeed.
Buying Experience
It's been a while, but I believe I bought it at Whole Latte Love on the net. The transaction was problem-free.
Three Month Followup
It's been 2 years now; details elsewhere on this page.