I was so afraid of buying this pack because of all the negative reviews. But finally I bought this on sale and I'm positively surprised! :) Here are my experiences with this pack:
This pack works fine. No bugs. Here is a great tip that I found from Reddit and what made me finally try this pack:
You have to turn off the autonomy of your sims from game settings so wedding and other parties which came with this pack will work properly. I haven't had any issues after turning autonomy off.
BUT for example wedding don't have a time limit like other parties do. So you don't know how much time you have before the event will be over. You'll always get a bronze award (even if your wedding was perfect) but you don't get any reward. So I'm not sure if these wedding themed parties are not supposed to have golden, silver and bronze awards like other parties do or is this a bug? But it's still fun to have these new parties that came with this pack.
Here are some other nice new stuff that I liked in this pack:
The new world Tartosa is beautiful.
Now you can dance slow dances together with other sims.
You can buy cute tea sets and serve tea.
Different kinds of wedding cakes. (I have Get to work DLC, too, so it's fun to create a bakery and sell cute wedding cakes.)
Some build & cas stuff.
I recommend to buy this on sale. Even if you are not so interested in wedding stuff this pack brings some other cool new stuff to the game. Of course I can't promise you won't encounter any bugs but you can refund this pack if it doesn't work.
(I refunded Dine out DLC back then when it was too buggy to play, Steam allowed the refund)
I haven't used any mods in Sims 4 but still some players who don't use mods are encountering bugs in this pack. To me nothing game breaking happened after downloading this.