I'm on 205/45-16 BFG SC2s.  Daily driver/hwy cruiser/canyon use only.
Pros:
-Much more dry grip compared to 21k mileage OEM Potenzas (yes, an unfair comparison, fresh tires vs. end-of-life tires.  No wet grip experience to date, still in a drought around here 

 )
-Significantly more comfortable (mostly/entirely due to additional sidewall of 205/45-16 sizing)
-Easily accessible/Dirt cheap ($85 ea after discounts, installed at my favorite local shop)
-I personally cannot find the limit of grip (too far outside my comfort zone)
Cons:
-Minor but noticeable loss of turn-in response.  (I have already "adjusted" and have no sense of regret)
-Initially somewhat noisy, somewhere between 500-1k miles they have quieted/my ears have adjusted and I don't hear them at all any more.