It sounds like you are going to have to buy one and just find out if you like using it or not. I would never pay $200, let alone $300 for one, tho. There are better deals around. Watch the auction houses, craigslist, and estate sales. I have bought 3. Paid $20 for the first one and $85 for the last one from an auction house... then realized it needed the bobbin winder replaced, so add $30 for that. Remember, MILLIONS and MILLIONS of them were made over about 3 decades and they never wear out. There are a ton of them 'out there'.
That being said, I just about never use mine. Once I found a 301 I liked it so much better. The 301 is just 5 lbs heavier, but is gear driven rather than belt driven. Belt drives are so wimpy compared to gear drives. But if all you plan to do with a FW is piece two layers of cotton together, it will be adequate. Forget sewing jeans or quilting, or anything heavier than cotton piecing.
As for the 'perfect tension/perfect stitches' myth, it varies from machine to machine. They all have to be cleaned and oiled well and the tension set properly to make that perfect stitch.