Without a doubt the visit to Libearty, the bear sanctuary, as this is restricted access and not generally available to tourists. We were given an exclusive guided tour for most of the morning and were able to see many bears. Note, the sanctuary is not a zoo and is no way a "commercial touristy" venue, itis a working wildlife concern.
Must mention Bran Castle in passing, as I'm fond of the book and films regarding Transylvanias most famous son...
The weather was hot at this time of year, mid 30s degrees C a good capacity water bottle is a must. We were able to re-fill at one or two points in the mountains from natural springs, Casmin will advise.
The weather can turn quickly though, always take a raincoat; when it does rain it won't hold back, but lasts about 30 minutes or so. The thunderstorms were great if you enjoy such things.
If you do the optional bear hide in the evening (which I recommend), this will be at dusk so sort out your camera before setting off; the red light emissions can scare off the beasts. The hide is well built and protected, you will be safe. Sit still and don't figit though!
If you can, take binoculars (these are good whilst in the hide even though the bears are only 30 metres or so away) and we saw chamois and eagles etc in the mountains.
Sun screen essential. Insect repellant needed on the beaver watch evening as it is by the river and again at dusk. The mountains seemed fairly clear of biting insects.
I may confirm there is no need to pre-load on garlic for these evening excursions.,
The hotel is comfortable and was kept clean daily to a high standard. You will need Lei for the Brasov day, but (at the time of my holiday) could pay the hotel honesty bar in Euro as well as Lei. You can pay for duty frees at the airport in Euro as well. You will need to pay Euro for the bear hide though.
Most Romanians I met in cafes etc spoke very good English, I shouldn't panic about a phrase book.
A couple of packets of jelly babies or whatever helps to maintain energy levels in the trekking days. You will make a picnic type lunch from the continental style breakfast, so a plastic lunch box would be useful.