It is obvious there has been alot of work on this course recently and I found it challenging and easy to navigate! Signage was excellent. It seemed evenly spread through wooded (more technical) holes and open park holes where you could work on your long game.Short and long tees provided a thorough test of my game.

Sure, some of the short tee holes were a bit short but when they were there was a technical component in the course design to keep you on your toes. Anything off of the fairway is in thick!

I was playing in a mini of the newly formed Jacksonville Rattlers and they were nice folks who you could tell love the game. They have great plans to expand disc golf throughout this lovely park. Their most recent improvements make it clear they are moving in the right direction.

Disclaimer: this course is in development.  But that's really not fair to say.  It's got 9 holes in, posts by every tee pad and the dirt tees are getting nicely worn in.  I'm played some courses that have been up for a few years that needed tons of work compared to this one, so I'd say this course is well on its way to being excellent.
Great hole layout - the holes here are well planned, challenging, and vary from right to left.  Even playing some of my favorite courses, I get to a particular hole (3 at Cain Park) and in my head I'm thinking screw this hole.  This one all of them were challenging, but seemed doable even on a first run out.
Excellent use of elevation - somehow this course manages to use a lot of elevation, but never play uphill.  I don't have a ton of power, so I hate playing uphill.  This course had several long downhill slopes, but there was always a catch.  4 is a nice shot up and down a little incline, but at the end it doglegs right off into the woods.  7 is a great downhill shot, but there's trees 2/3rds of the way down blocking you, so you still have to throw high or a long annhyzer.
Some of the holes here were pretty forgiving, for instance 4:  If you throw a low power shot that fades way left, you're farther away but you have a straight shot at the hole, where as if you get right up close in the middle, you m,ay be throwing out and around some trees on your approach.
The park wasn't crowded when I was there, and the holes don't come in conflict with the walking paths all that often.
The locals here were a blast to play with, laid back and friendly.

Several places the holes cross over one another, or you're walking back up the fairway you just finished to get to the next tee.  On a crowded day or in a tourney situation, you'll be in each other's way on a few holes.
As with many East Texas courses, thorns are an issue here.  When you walk up to the tee and the locals say "stay out of that bush, that's the Demon Bush," they are not freaking kidding.  Stay clear of the woods and the bushes in the fairway on hole 3, they're killers. 
I'm not a fan of the baskets here.  I've gotten spoiled by Innova Discatchers.  These have red tops, which are a little harder to see.  Also, on the Innova's the basket has a hard edge, and the basket opens out so it's catches the disc better.  At Nichols the baskets sides are parallel all the way around, so I had a couple approaches that would have gone in on a Discatcher, but bounced out here.  It's nitpicky I know, but it's the truth.  I guess you could say it just raises the challenge here.

Take a guide your first time out, navigation isn't hard, but two or three holes you can't see the basket from the tee (but those were some of my favorite holes) and a couple times the next tee is a good walk from where you are.  With no signs yet and I didn't have a map, I would have been frustrated playing alone and not liked this course as much as it deserves.  Even if they stop right now and don't do any more work, this is a great course.  9 holes, good challenges, good birdie opportunities, elevation, short and long holes.  It didn't feel like a short easy 9.  If they improve what's there and add another 9, this will be a must play in East Texas.  I compare this to Cain Park in Athens (my favorite course) but with no tunnel holes.
The locals said they play every Tuesday and Thursday at 6:30, I recommend joining them for a great round in Jacksonville.