We arrived here after our month in Turkey, it was hot and we were excited. The weather averaged at about 42 degrees, there was dust, there was rain and the music didn't end till 6am (and started again at 9am). Although I had an amazing time and made some really awesome friends I'm not 100% sure I could do it again. We both got extremely sick afterwords, I came very close to calling myself an ambulance... but we recovered!!.
As far as festivals in Europe go, I honestly think there are a lot of better options that sziget (not that it wasn't amazing) we went because it was right under our noses and we didn't have to think very hard or plan for it... We also were just generally uninformed about the other festivals that were happening around us (if you're there in summer there are literally millions). Festivals werent our priority on this trip so we didn't give them much thought but next time I'm definitely going to plan with more festivals in mind... (I have a massive list already)
For anyone planning on going to Sziget, its worth getting the 7 day pass to allow you to get there early on the first day so that you can find a camping spot in the shade (which will change your life). We pre-ordered the tent package which was $80 for the week (in hindsight it would have been cheaper to just buy one from a shop in Budapest). You could keep the tent if you wanted but we returned it at the end and got 20 euro back. The tent was incredibly small so my backpack had to stay outside the entire time (it had snails on it by the end of the week and got very wet in the rain).
Food inside the festival is fairly affordable, we usually got dinner for $7 (they don't use the euro in Hungary). There is a MASSIVE supermarket called Auchan about a 10 minute walk from the entrance to the festival. We went there and ate our breakfast and bought fruit, bread and water to take back with us. Alcohol is pretty cheap in the supermarket too and there are lots of sneaky ways to get it past the guards at the gates disguised as groceries (if that is what you wanna do). There are also showers that were actually pretty good, scattered across the festival. The best time (so you don't have to cue) is around 3 in the afternoon or really really early in the morning (5am ish).
During that day you could get the train in and out of the festival into the city. Some people stayed in Airbnbs/hostels and only came into the festival at night (which, given the heat and the dust was probably a clever idea).
The music was funnily enough a small part of what made Sziget what it was for me. I wasn't particularly excited for any specific artists that were playing but I loved all of it! Sziget was like another universe, one that we shared with 450 000 other people from all around the world!! It was super cool!!
We got a transport pass for $12 that gave us unlimited transport for 4 days during the festival and also gave us free entry into one of the city's Baths. Entry to Szechenyi is usually $21. Make sure you give yourself at least 3 hours to enjoy your time here. Although it was 38 degrees outside and there wasn't much difference between the thermal waters and the air the hot water was still really relaxing (and the cold pool was literally the best thing that has ever happened to me). It was our first proper shower in over 3 days so we really savored our time here. The baths continue inside as well (although I don't have any photos) so make sure you explore the entire complex before you leave.
Budapest was an extremely pleasant surprise and had we had more time in the actually city I think it could have been one of my favorites. It was cheap because they don't use the euro and had lots of funky bars and restaurants. We stayed in the city for 2 nights (1 before and 1 after the festival) in Krisco apartments which were incredibly luxurious for the price we paid ($25 each a night). We were able to cook our own food and sleep in a big double bed (which was a massive deal after our month in hostels and sleeping on the beach in Turkey and our week in a tent at Sziget).