I've been fat biking for about 4 years now. I've learned a lot about what makes it fun. I've learned a lot more about what makes it not fun. Just like any sport on snow, you can decide you don't like it your first attempt. There are some things you need to know before you can make a decision about whether or not you like fat biking. (There are many more factors that come into play for you to make a decision about whether you should buy a fat bike.)
The biggest factor in enjoying fat biking is managing your expectations. If you expect fat biking to be exactly like mountain biking, you will likely get discouraged unless the conditions are perfect. Comparing fat biking to mountain biking is like comparing cyclocross to road racing. They have similarities, but you will probably spend some time off your bike pushing it. I've spent more time than I care to admit walking a fat bike through snow drifts and fresh snow.
Don't expect the same conditions on the same trail two different days. When it's really cold, the snow can turn into a sugary consistency. If it's warm, the snow turns to mashed potatoes. If the conditions are just right, the trail will pack out and it will get better each time it's ridden. I have never experienced the same conditions two separate days. It is either better or worse, never the same.
On a similar note, you cannot expect the same conditions in the afternoon or evening as in the morning. Winds may pick up, temperatures change, more people use the trails. So if someone says the trails are perfect, give them a try, just keep an open mind because that could change. Often the trail is better on the way back compared to the way there, but could be worse if it doesn't pack down.
Don't expect your skills and abilities to directly transfer from mountain biking to fat biking. If you are a very well rounded rider, you'll be fine. However, even if you are a strong rider on the dirt, riding on the snow could become frustrating. Snow riding requires you to shift your weight to gain and keep traction. You will be forced to learn these skills as well as how to take a slam. The trail can be packed well enough and then you hit a soft spot or get off trail slightly and you find yourself rolling in the deep. Tuck and roll, you'll be fine. It's easier to learn how to take a slam in the snow than on dirt. Change your mindset about what you should be able to do. Be humble about it also. You'll get faster on snow and on dirt.
When you do decide to buy a fat bike, there are some things you should keep in mind to avoid frustrations also. You cannot expect to be able to swap wheels and tires between bikes. This year bikes have started to become more standardized with 190mm or 197mm rear hubs and 150mm front hubs. This allows bikes to have either 4" or 5" tires. But you can still find bikes with 135mm front and rear hubs, or 142mm front hubs and 170mm rear hubs. As long as you are expecting this, you shouldn't be disappointed.
If you want the conditions to be perfect, there are some places that have really figured out how to groom trails. Powder Mountain's Fat Bike Nationals course is amazing, but they do charge for access to it. The cost to keep the trail in fantastic shape is what you're paying for. If you don't want to deal with all of the inconsistencies of fat biking, this is a great way to ensure a better experience. But sometimes the worst experiences become the best memories.