Did I like this trail? Yes, a lot! It is very unusual for a mountain trail in Europe to stay up on the crest for such a long time - with hardly any road walks! Views were spectacular although I missed a lot due to bad weather. Would I recommend it to a friend? Yes, of course - I think this truly is a hidden gem! Still you will need a sense of adventure - very few people speak English and everythings is in Kyrillic. Plus this is the poorest country in the EU ...
Trail marking is quite good in the Western part. In the Easter half you should have a GPS with you to avoid getting lost. It helps to walk from West to East - other hikers have complained that the trail marking is worse the other direction. Technically the trail is very easy - only one bit in the middle part requires steel cables and climbing but there is an alternative route around it.
Water is not a big issue on Kom Emine. There are plenty of springs along the trail which are also marked in the guidebook or on the OSM maps - you just have to plan ahead a bit. I never carried more than three litres and never treated my water.
Bulgaria is also heaven for coffee drinkers - there are coffee machines in every big. Biggest national specialty is soft feta cheese which you will get for breakfast, grated over your French Fries and of cours in Shopska Salad. Expect to be offered Raki schnapps a lot ... At the end of my trip I had some of the best sea food ever at the Black Sea Coast! In all but very cheap restaurants there is a bilingual or English menu. The translation is usually very creative but at least you get a vague idea of what you are ordering.
There are obituaries plastered everywhere because Bulgarians do this not only for their recently deceased but also to commemorate anniversaries. And one last good news: Other than Romania there are hardly any aggressive dogs!