I have a slightly different opinion,
If was a tool that I ever purchased that has exceed any of my expectations or usability, is the Nova G3 chuck with its custom 50mm jaws.
I have purchased other jaws for this chuck, including the dedicated pen turning blank jaws for "C" series lathe chucks (as the G3 is).
There isn't much that I can't "grab" with this chuck, with a particular focus to the chucks own center jaws, which allow for the holding of drill chucks, any M2 sized tools, and anything that is not small then 15mm or so.
Without removing the chuck, I do most of my work, from pens, to bowls, vases, plates, platters, and anything I feel like.
If there is any accessory that can be attached at the end of the thread head stock shaft, the Nova G3 is it...!
You can find chucks the same size as the Nova G3 for a lot more money too, I have not tried those more expensive ones but, and using mine on a Nova 1624-44 Lathe, I've repeatedly turned blanks or chunks of wood such as full smaller tree roots, to the maximum size possible to turn in this lathe size and the G3 has never miss a bit or show any weaknesses.
I know this as I service the chuck regularly and inspect for any problem on the making, has been 5 years and I can consistently turn an unbalanced, heavy, big and irregular chunk of wood, with some nasty catches and jars on the spindle/chuck and turn a pen next, inserting the mandrel in the chucks center with no wobbles or out of weck in some way.
There are 4 important details to consider when using this chuck (or any other chuck);
Firstly, try to get the chuck with the same size as your lathe threaded shaft, (no adapter) you will get the best accuracy and less problems this way.
Secondly, use the chuck with and adapter but buy this adapter from the same brand as the chuck, many less expensive adapters are more trouble that they are worth and in fact the cause of many chucks wobbling...!
Use a proper plastic washer (now readily available...!) between the chuck and the lathes' shaft/spindle
Take attention to the reverse on the lathe and what it can do to the chuck if not tight right. There is a grab screw to secure the chuck to the lathes' threaded shaft, this screw should be firmly tighten after the chuck is threaded firmly but not over tighten to the shaft (the plastic washer is essential here).
When turning the lathe in reverse, and depending on what you are turning, catches, etc., the chuck can come loose, and start wobbling when in forwards position so, keep and eye on it...!
Apart from keeping it clean and lubricated (slightly on the rotation/friction parts), the chuck is trouble free and very durable.
About 95% of people that start as pen turners, will develop interest for other type and size turnings, any mini or midi lathe will become a very versatile machine with one of these chucks, allowing for the turning of most if not all the new pieces, one wishes to try turning...!
If investing wisely and smartly is your goal, this is a good example...!
These are my views from experience, I will stick with them...!:wink::biggrin:
Good luck
Cheers
George