The pre-departure support from PMGY was so useful, I would recommend using it as much as possible! Josh was great to speak to over the phone, friendly and informal - really knowledgeable about the programmes.
I spent 4 weeks in Tanzania and I wish I had gone earlier and stayed longer as the experience just gets more enjoyable as you get to know the other volunteers and the staff. The accommodation is relatively basic - there was no WiFi while I was there (not always the case) and the showers aren't consistently warm - but it was extremely social, comfortable and I wouldn't change anything major. The house Mama's cook amazing food, just be open to trying some new things and you'll never go hungry! The Mulberry (bar and restaurant on-site) serves more Western foods and is a great little social hub to have right next door.
The staff in-country are fantastic and there is always someone available to chat to and ask any questions or reports any concerns. I did an orphanage placement and a member of staff escorted me and the other volunteer on the first day to show us the journey and introduce us. I took food every day for the kids breakfast and toys (from the resources shelves at the volunteer house). Apart from playing with the children, I helped with food preparation and keeping the orphanage clean and tidy.
I would definitely recommend this experience if you're willing to be spontaneous and settle into the 'pole pole' lifestyle in Tanzania :)