I wouldn't recommend this trail for the visitor. You're too close to the highway and it doesn't feel like a true "Alaska Wilderness" hike.
However, the 3 trails are worthwhile for their intermittent views of Turnagain Arm which is a beautiful area of Alaska. The trails are also good for preseason hiking as they are one of the first places to lose its snow. Since they are relatively easy to hike, they are also worthwhile if you have kids or if you're in bad shape. You can start at either end or there is parking for each of the 4 points if you just want to do a section.
A better way to see Turnagain Arm is either biking along the Seward Highway or taking the many mountain hikes along the way (a list is included in the aforementioned trail).
McHugh Park has a great picnic area with great views as well as grills and bathrooms. I recommend a picnic and then a hike after hamburgers as a family outing with young kids.
Some of the locals refer to this as the Old Johnson Trail (not to be confused with Johnson Pass).
If you have the time, check out Potter Marsh. A long and winding boardwalk meanders around the marsh. Bird watchers will be particularly pleased.
There is a $5 parking fee (bring exact amount) at both the Potter Marsh and McHugh Creek parking lots. The price for an annual parking pass is $60. You can purchase a pass at the Federal Building at 4th and F or the Atwood Building on 7th and E, 13th Floor.
Turnagain Arm gets its name from when Captain Cook sailed up his eponymous Inlet looking for the Northwest Passage. When he turned into the Arm he realized he was mistaken and had to "Turn Again".