Not as difficult as people are saying! Hiked this in 2 and a half days but we were fairly rushing, I'd rank this in difficulty as 4/10 but It all depends on what you're used to (I'm used to doing mountains/harder trails).
Extremely muddy (in late spring when we went) but as long as you bring spare pants/socks, it isn't bad. You can avoid about 80% of the mud as there are alternate ways to walk on the trail. But there are some parts where getting muddy is basically unavoidable.There are plenty of creeks and water sources nearby the camping areas where you can clean your boots/clothing and just dry them around a campfire!
The driftwood/wood source were fairly wet when I went but it was just because it mostly rained the entire time. If the forecast is wet, bring some driftwood if you have room.
There are food caches at all the camping areas, so hanging your food from bears/critters is not necessary.

My wife and I just finished hiking a portion of the JDF trail this Easter week end, We're in our late 40's/early 50's and are kinda new to multi-day hiking, but are keen to get out there and give it a go. We chose this particular trail not only for it's incredible scenery but also it's relatively small elevation gain and lack of snow at this time of year..
Our route was China Beach to Bear Beach (9km) for day 1, back to Mystic Beach (7km) for day 2, returning to the car (2km) for day 3.

We caught the 7am ferry from Tsawwassen and got to CB at about 10:30am. The parking lot was almost full when we arrived and a shuttle bus (guy in a pickup) was just leaving. If you want to to hike the trail one-way, the shuttle might be worth considering.

Of course once we started hiking it didn't take long for a heavy rainfall to hit in spite of the "Sunny" forecast but c'est la vie. . .that's the west coast for ya. As for the trail itself, yes it was as muddy as advertised but we didn't mind. It was actually fun sticking to the mucky trail centre rather than trying to avoid the inevitable. And although I'm not a big fan of hiking through previously logged areas as in portions of this hike, I realize that can be difficult to avoid in much of BC.
I was also surprised how poorly marked the trail was in some sections (5-6km) and how overgrown it was in others. It was manageable, however, and even enhanced a wonderful feeling of "being away from it all" which is a big draw of this trail.

For us, one particular section of the trail was noteworthy. We found part of the steep descent to Bear Beach (8km) to be quite difficult--not Moderate as shown on the map. I suppose it didn't help that there was a sudden downpour of rain just as we started negotiating that crazy-steep-slippery-worn-out-log-stairwell with its slimy- over-sized-leaning-handrail. What the heck was that? .

Anyway, our overall experience on the Juan de Fuca Trail was very positive. It was probably a bit tougher for us than most mainly due to our level of fitness and experience, but don't take it lightly and make sure you are well prepared. Good equipment and the right clothing and footwear make a real difference.

So if this trail can be this popular while being so rugged, imagine how popular it would be with some trail improvements. . . and therein lies the dilemma of the JFD Trail, right?

Having travelled this trail a number of times it can be enjoyed a number of ways. Short day hike challenges to tackling the entire trail as an adventure. Every bit as good as the West Coast Trail this complement of easy access and fun tidal route finding is a great warm-up for its longer cousin to the north.