You don't need an FCT to download more trains. You'll only be limited to 100MB per day. An FCT will give you unlimited amount of downloads and at a much higher speed than a 5-10kbs.
John is right, and I think it is money well spent. I bought a lifetime FCT, it took a day or so, but now I can download a lot, and the speed is awsome! It really speeds up the download!!!!!
As stated above, a FCT is not mandatory for supported versions, but I would recommend getting one, as download speeds are very slow (~5KB/S) and downloads are limited to 100MB/day.
