I suppose some aspects of SMD construction are beneficial, especially in a device centered around an op amp, but not all, and not when repair is needed.
This is very true - the proper equipment required to work on SMD boards is around $100k. Most tech's can't afford this investment, and if a manufacturer using SMD technology goes bust - then your precious unit, when it develops a problem will be toast. Even with most manufacturers that use SMD technology, if there is a fault - the "repair" is a new board.
Personally I would never buy a piece of audio kit using SMD technology - seen too many disasters. If you do buy an SMD based unit you have to assume it will need replacing within 5 years.