Do the trip. Don't put it off. It was a great trip all round (e.g. making new friends from different parts of Oz, not having to worry about accommodation and finding activities to do, covered so many places in a month - tour provided great insight into Southern America). I'm glad to say that I've made tight friendships with some of the people on the tour.
Only downsides were the Contiki Cough that knocked out of all the tour group and the occasional long bus trips (e.g. Santa Fe to Amarillo, St Augustines to Savannah and than to Rayleigh).
Highlights of the trip include New Years Eve in New Orleans (be careful of the Hurricane and Grenade cocktails), Las Vegas, Grand Canyon, Miami, For Worth, Washington and Cocoa Beach / JFK Space Centre (we got to see a SpaceX rocket take off at night). However St Augustine, Georgia and the Carolinas weren't that exciting, but it was a necessary evil to get from Florida to Washington.
Luckily the group I was with were great (Mainly Aussies from Qld and SA) with the odd few from Canada and NZ. Due to the time of the year, most of the people on tour were teachers and boy did they know how to party. 2/3 of the group were in their early 20s and the remainder were in the late 20s to mid 30s. Reasonably good dynamic with some odd moments.
Food was good overall (I was actually surprised). Most of the breakfast meals included hot items (e.g. bacon and eggs). Occasionally breakfast only included cereal, milk and a piece of fruit etc. The provided dinners were fine (e.g. pub quality and BBQ meats in Texas / Florida).
And yes, there was lots of partying (2 out of 3 nights were spent on drinking).
Despite negative reviews about accomodation from past reviews, accommodation for our trip was good overall (apparently Contiki HQ have been able to secure better deals due to a downturn in the tourism industry in the USA during 2019), however the location of some of the accommodation was a bit far to the city centre (e.g. Memphis, DC), so be prepared to use Uber frequently if you're experiencing the night life in certain cities.
There were semi-frequent stops to Walmart, so it was a good opportunity to stock up on beef jerky... and alcohol.
In terms of budget, you're looking at spending $3.5k to $4k throughout the whole month (e.g. meals at restaurants, alcohol, optional activities, gifts, shopping). Low Aussie dollar had a big impact on purchasing power.