I have the 1624-44 and pretty much like it.  All I know for sure is that turning at below 250 rpm is not much fun anyway.  I try to balance or rough out my big nasty stuff some other way.  I think The variable speed drive for the Nova has been discontinued.  I think it was close to $1000 when last available.   Maybe if you know motors and drives there are other options?  I do have and frequently use the bowl turning tool rest holder for this lathe.  I personally spent the extra money the variable speed would have cost on the bowl turning outrigger and and extension bed and and Easy Wood turning tool and a Thompson bowl gouge.  I can change speeds when I need to.  I often need to stop for a couple of minutes between stages of turning anyway. And I thought the add on motor was expensive for what it adds.  Even if the variable speed is still available I will be lookin at a CBN wheel instead.

My thought is that selling the belt drive Nova and buying a variable speed lathe would result in a much better lathe overall for not a lot more money.  For instance the Nova that is built as a variable speed is a better head design than the single bearing of the 16-24.  For me the 16-24 got me into turning when I did not want a bigger or more expensive lathe. It was a step up from my 11" Reeves drive Delta.   And it is still good for what I do.  I do run my eyes and fingers over the Laguna when I go to Woodcraft to buy glue and sanding supplies.

So to me the 16-24 is a "it is what it is" type of tool.  And I guess there is a reason the used ones sell cheap.

I doubt if there is an inexpensive way to handle the "turn anything that comes" idea for a lathe.  And I have come to realize that is not something I want to gear up for.  I mostly have turned reel seats and handles for fishing rods with my lathe so I am at the other end of the spectrum.