I have the PQ-1500SL, purchased from Amazon. I have not used the other models you listed. I am so happy with this model! That being said, my understanding is that all of these models are quite similar so depending on what features you're looking for, you're likely to be very happy with whatever model you choose. I also own another Brother (the CS-6000i - which for anyone looking for an affordable beginner/take to classes machine, i love this little guy!) so the power cords/pedals/misc accessories are interchangeable. The deciding factors for me were:
1) Price: The 1500 was definitely more in my budget range, so the TL-2010 was a tough sell for me right off the bat.
2) Accessories: The 1500 comes with everything I use regularly: walking foot, free motion foot, 1/4" foot, knee lift, large tabletop add on table, thread cutter, needle down (though not a button for needle up - you have to crank it manually)
3) Harp space: I haven't read the exact specs on the other models, but the 1500 is plenty large enough to do basic FMQ (I've done up to queen size). I assume all the models are roughly similar.
4) Adjustable feed dogs: I like this feature. I don't know how often you sew some other fabrics (faux fur, interior decorating fabrics, clothing fabrics, etc.) but I found it to be a lot more helpful than I was expecting. I also like the pin-feed feature, I'm not sure if the other models you list have that.
5) Speed control: I don't really miss it. I find the foot pedal is plenty responsive.
I have no regrets! Whatever you choose I'm sure you'll be thrilled, they all sound like great models.