I've done walk up, regular FP, WCT preferred viewing and dessert party for WoC. I will say that we got extremely lucky with the walk up spot and I have never relied on that as my viewing plan (We weren't planning to watch it at all but a pretty good spot was still available very close to show time when we were walking by so we grabbed it). Here's how I would break it down (excluding the walk up) from least desirable to most desirable in my book.
Regular FP: Getting the FP is painless (as long as you or someone in your party is in DCA at some point in the morning). There really isn't a need to rush over there first thing, IMO. BUT, if you want a decent viewing spot in your FP area, you will need to arrive well ahead of time. Since all my WoC viewings have included children under 4' and viewing is standing room only, getting a spot at the railing/front of a section is very important to us as I will not hold my kids up the whole show (both for my arms/shoulders' sake and the sake of those behind us). We usually mitigate the wait somewhat by getting food in the Wharf area and eating while we wait (you can sit down while waiting/prior to the show but everyone must stand up for showtime). You can still have a very enjoyable viewing experience with regular FP, you just have to commit more waiting time and there's more risk of a subpar view, particularly for kids.
WCT Preferred Viewing: We have enjoyed the food at WCT both times we've done this. The last time we had 2 people with special dietary needs (Gluten Free and Dairy Free) and they were very accommodating and the food was still very good. We do the meal mid-late afternoon and just snack before and after. That offsets the cost a bit since we're not buying a full lunch and dinner in the parks (and we likely would have bought most/all of those snacks anyway!). The pricing starts to seem a little more reasonable if you think of it as 2 meals.

We arrived in the viewing area approximately 30 minutes before show time and have had great viewing both times.
Dessert Party: Can you say SEATS and TABLES?!? Definitely the best view (at least from the high table we had) as well- particularly for kids. The desserts, cheese and fruit was good too but I wish they had a 'kids plate' that was smaller so I didn't feel like so much was wasted. You can take it with you if you want but I just didn't see the rest getting eaten and didn't want to haul it around. We did not arrive crazy early as I see some people posting about and were still very happy with our table but its certainly a premium price...but it's a splurge I feel is worth it. If our last trip hadn't been last minute and the DP wasn't sold out, we would have done it again for sure (we did the WCT package instead).