I absolutely love my Featherweight. However, they are 60-100 year old machines, so when you buy one it's not guaranteed to run like new. It also requires regular oiling and maintenance, more than modern machines.
If you want a couple modern conveniences, consider the Janome 3160. It's not much heavier than the Jem, but has a larger throat, needle threader, thread cutter, needle up/down, and a couple other features. It also has a nice quiet motor. I'm also a fan of the Pfaff Passport, which includes IDT.
I recommend you try before you buy - you might discover that there are features you want, or things that bother you in a machine regardless of other people's recommendations.