Well if the shows were as good as they were in Dallas, it's more than worth the trip.
Even if Wrestlemania is a flop, the whole experience of being there is worth it (and addicting). I do the travel packages because it gives me peace at mind that I have everything booked, but you can also still try to upgrade your tickets by buying tickets to individual events when they go on sale separately, and then simply scalp your package tickets (that is if you go with one of the cheaper packages but still want to get floor seats for NXT or Raw, for example).
San Jose for Mania 31 had a much better atmosphere than Dallas though. I guess that's because Dallas is a much bigger city it just felt like everything was a lot more spread out. In San Jose everything was easily within walking distance. The WWE hotel was a couple blocks from our package hotel and you would see wrestlers walking around during the day time, whereas in Dallas nothing was all that close unless you had the Wrestlecon hotel which was right next to the convention center.
Regardless, there are still a lot of people who are there for the wrestling weekend and that makes for an awesome atmosphere. The parties Friday night are amazing (that's how I ended up drinking with Alicia Fox and talked to her boyfriend for a while). Saturday night after the HOF is always fun, and then the after party after Mania is a blast. The Raw after Mania is by far the best atmosphere you will ever experience for a Raw event.