Here's a few statistical measures comparing his play through 3 games this year to all of last year. I was very pessimistic about Bortles coming into the year but honestly, I've been impressed with his progress through 3 games. 
 
TD%
2014: 2.3
2015: 4.7
 
INT%
2014: 3.6
2015: 2.8
 
Yards/attempt
2014: 6.1
2015: 6.6
 
Adjusted net yards/attempt
2014: 3.81 (27/27 with at least 10 starts)
2015: 5.69 (20/32 with at least 2 starts)
 
DVOA
2014: -40.7% (43/44 with at least 100 attempts)
2015: -14.7% (21/32 with at least 45 attempts)
 
DYAR
2014: -955 (44/44 with at least 100 attempts)
2015: -26 (21/32 with at least 45 attempts)
 
PFF Grade
2014: -38.9 (28/28 with at least 50% of snaps)
2015: -2.4 (18/30 with at least 50% of snaps)
 
Really the only place he isn't significantly better than last year is completion% which is mostly (but not totally) explained by a higher drop rate. Also he's been more aggressive with throwing downfield, since his YPA is actually higher with the lower completion.  In the other categories he's gone from the worst starting QB in the NFL to just a below-average starter through 3 games this year... which to me is pretty good for where he is in his development. 
 
Edit: I didn't read the thread but from this page it seems like people are comparing him to Blaine. Last year, sure, I could see that. But this year that's asinine. Blaine never even approached playing as well as Blake has played so far. 

---