I'm pretty partial to this one since I grew up in the neighborhood and came here a lot growing up but it's nice for a walk. I would definitely say don't run it because you could trip over a small headstone or grave marker and wreck your day not to mention if there are people there grieving, the last thing they want is you running them over.
I hiked the trail and managed to accumulate 8.2 miles in total of decent hiking. I prefer the wooded area more than the cut outs, but they were nice as well. The orange blazed/flagged trail was great, with numerous blazes/flags to keep you on track. This was not really the case with other off shoots or appendages of the 2.9 Orange blazed long trail. The only time I could see where I was is when I would come across an intersection marker. For a moment there I didn't know where I was, or the direction I was heading. It would be much more enjoyable if the paths were indicated properly. It is a great park nevertheless. It is well maintained, clean, with wildlife visually present. A great place to be.
I have always lived near Mt. Hope Cemetery and it has been my place to run with my dogs, hike and mountain bike and party when I was a teen. I am not sure who put this 14+ mile trail in but I suppose you could take all the many trails and end to end get 14+ miles. It is mainly technical short trails all over the place and mountain biking is not "allowed" off road there; but a lot of us do it because of the technical challenge in the old hilly sections. Having lived literally across the street or on the other side of Highland Park I know it like the back of my hand. If you are not careful there are many low and hidden headstones that will take you and your bike out. Also, many old rusted iron fence pickets and water pipes that will impale you. It happened to my friend and he ended up in Highland Hospital; though he was trying to hop the fence. Be respectful it is after all a cemetery. The residents of the cemetery do not complain :) but some of the visitors find it disrespectful so be stealthy and stick to the old hilly areas and do not hit any headstones or cause damage!
You can also tie this in with the city trails network starting there and then head east through the back high ground areas of Highland Park then Pinicle hill (private land but open with lots of steep climbs), Cobbs Hill/Washington Groove park (also not biking legal so be careful) and then down Winton Road to Tryon Park, West Bay (biking is legal)... and so on. It is a long ride, many climbs and some really challenging trails. Other than some quick rides on pavement between sections it is all off road single track. Most people do not even realize you can ride for 30+ miles of single track in the middle of Rochester with a few thousand feet of climbs when you take all the many park trails in. It takes some time to find your way but look on line at Tryon Bike, GROC and other helpful sites that have some trails maps. Explore it and you will not be disappointed but, again do not be to obvious! Not many people in these areas but rarely, someone will yell at you if you are in one of the "no ride" sections.