I'm looking at getting a 308sw soon, a lovely looking car inside and out
My wife has one:
+Humungous boot, bigger than most cars of any class but particularly large for a car of this overall size (bigger than Octavia Estate, Civic Tourer, Leon ST etc)
+Good levels of kit for the price bracket (front/back sensors, reversing camera, 10" touchscreen, Nav, LED lights etc)
+I think it looks pretty smart in general
+Overall good value as a second-hand buy, low residuals mean you can pick up new models pretty cheap at a point where the depreciation curve will be closer to 'normal' cars. I would be wary of getting a brand new one unless if was a particularly good discount (over 25%).
-Lacks a performance engine, the best petrol you can get is 1.2 130hp (which is actually pretty decent for what it is, but clearly not going to compete with what you can get in other cars)
-Touchscreen can be a bit slow at times especially inputting to sat nav. Nearly all reviews moan about the climate control being on the touchscreen rather than a physical dial, but that bothers me less, given it gets touched maybe a couple of times a month...
-Higher trim levels come with bigger alloys, which may look marginally better but increases running costs
-Used to have creaking noise when pulling off (only really noticeable from outside), this is a known issue and was fairly easily fixed under warranty but makes you wonder about what other issues it might bring up.