I will break it down into sections for you.
Section 1 - From the headwaters downstream to Riparian Park. This area runs from Lititz Springs Park downstream through town. It is channelized, is cold enough to fish but access is difficult and not pretty to fish. Also hardly any fish hold here due to poor habitat. There is a section of this that is posted beside the Lititz Sportsman Association's hatchery. Look elsewhere.
Section 2 - Riparian Park is stocked by the club. It has nice habitat but gets pounded by anglers and virtually all the fish get yanked out.
Sometimes you will get a holdover rouge this time of year but its likely not worth it. This section certainly stays cold. You will know when you reach the end by the posted signs.
Section 3 - The Banta Property is a large section that looks everything like a classic spring creek and it holds fish. Entirely posted. Dont fish here.
Section 4 - Millport Conservancy is a badge only C&R area. If you are a member of TU you can buy a year pass for something like 20 bucks. It was restored, has great habitat, gets stocked and the water runs cooler. Wonderful area to fish if you buy the badge.
Section 5 - From the end of the conservancy downstream to the beginning of the C&R area. Area has ok habitat but generally poor. Open fields with shallow water and electric fences including farm animals. There is at least one bull to watch out for, but he has been friendly thus far. . IMO not worth fishing but I have caught some of the rouge fish that leave the conservancy here. You will have to park in the lower C&R area and walk the whole way up. generally not worth your time. The water begins to really warm here on hot days.
Section 6 - The C&R area. This area can be good at the right time of year. This is probably not a good time as I would imagine it would be too warm for C&R fishing. Good habitat and restored.
Section 7 - Below the C&R area to the mouth. Mix of open and posted land. Habitat is fair to good. Fish will move down here but again it is likely warm.
Wild Rainbows have been turning up from what I hear but not in the numbers that make it an excellent wild trout fishery. Maybe one day.
Hope I helped. If I was you. Id fish somewhere else.