As mentioned above, there are various pros and cons associated with the Avanti. If possible take the time to read through the threads linked above.
From a passenger perspective the cabin is spacious and comfortable, fully stand-up, and can maintain near sea-level pressurisation upto FL240.
If you want to bring down the cabin temp prior to the arrival of pax then a portable air conditioning unit can be used in the cabin for 20-30 mins beforehand. Otherwise the environmental control system is highly efficient and at larger airports one can usually make the cabin comfortable during taxi.
Some Avanti news.