Buy it and enjoy it. I have two and love them. I have made the tops to several quilts on mine. I just oil it after a day's sewing on it, and keep going. They are so easy to maintain. I bought my first one on Ebay, and was very forunate that the seller packed it well. I too was hesitant about buying there, but I truly wanted one so I took the plunge.
When you get it and start using your little gem, you will wonder why you waited so long to buy one. I haven't found mine to be tempermental, but machines are like people I guess they are all a little different.
One quick reminder, A couple of times I have had thread to catch in the bobbin case area, and have had to take that section apart. There is a tiny and I mean tiny screw that holds the bobbin section together. I have a small plastic cup like those on the top of cough syrup or dayquil bottles that I keep in my case just for this tiny screw, to keep from losing it. I also place my featherweights on a towel when I get ready to service them, and this helps to keep the screws from rolling off of the table.
I am not advertising for this individual, but I purchased the book (in black and white) titled "The Featherweight 221 and I" by David McCallum, it is the best purchase I ever made I think. The book is fully illustrated and every time I need to do any thing to my babies, I drag this book out. (I took it apart put the pages in plastic sleeves and put it all in a 3 ring binder, along with all other books or notes on Featherweights. I have manuals for mine, but this book is much better I think. A good site is Featherweight RX.
Have fun.