Long term is very subjective, as duration and severity of use as well as environment come into play.
Up here, I haven't been impressed with any of the cheap Chinese winches. They're painfully slow, and as a result eat up a lot of battery capacity on longer pulls. That often results in stops to allow the alternator to "catch up". I see a greater frequency of solenoid failures, and the cable termination can be hit or miss, which becomes more of an issue as corrosion sets in.
Now this is in more of an extreme environment than most people in the Lower 48 ever see. A typical trail ride can require multiple full-pull winch extractions, depending on how the conditions are that day. Water crossings and mud are features on the majority of trails, which add to the strain on the equipment. We
use our winches- a lot.
The guys who are most successful with them have taken the time to ensure all of the connections are properly terminated and protected. Some have gone so far as to disassemble and reassemble them, to ensure they were put together and lubricated properly from the factory. Many of them have eventually upgraded the solenoids to a better quality brand- usually after a failure. Some guys swear by them for their bang-for-the-buck performance- espeically those that got their Champion winch on clearnace at Costco.
Again, this is a harsh environment on
any electrical equipment. I've literally been in life-or-death situations (mostly due to my own stupidity) where the winch has been the deciding factor. I don't like having doubts about whether or not the winch is going to turn when I hit that button.
If I was in a drier and more temperate climate, I would consider one. Then again, when I lived in the Lower 48 I didn't own a winch and got by primarily with simpler recovery devices and more manual labor. Tugging, digging, and stacking usually got the job done. However, the difference between that Smittybuilt and a basic
Warn M8000 about $100, which given my experience makes the Warn the better deal- even without the synthetic line. YMMV.
For the record, I run a Warn 8274-50. When my Land Rover is done, it will transfer from my Jeep after a mild rebuild (preventative maintenance). After nearly 10 years of hard use, I figure it's due a refresh. It wasn't cheap back then, even though it was about $700 less than it is now. I considered it an investment, and still do.
When it comes time to buy another winch (for the Jeep or another vehicle), I will likely weigh my options. My first choice is to find an old 8274 on Craigslist and rebuild it. My second choice is a Warn M8000, which I liked a lot once I cut the cable back to 80'. A premium-line Superwinch or Ramsey will also be in the running. Probably last on the list will be one of the various Chinese winches.
..but they will at least make the list.
As far as the synthetic line goes, I would suggest using a winch cover and keeping the line clean to prevent it from degrading from the sun or chafing- especially if you won't be using it often. Nothing more frustrating than pulling the rope out and having it break- multiple times. Other than being extremely cheap, that's the main reason I haven't converted over yet from steel.