Although Rigol are about the best Chinese supplier, the general standard of software quality from China is poor, and once it is working enough to ship, you're unlikely to see any updates, or get any support - all they care about is shifting boxes.
Things like remote control are a minority feature and you can't expect any serious effort to have been put into testing. Even once bugs are found by users in the field, fixes will be a long tome coming, if they come at all.
Agilent have decades of experience making instruments, and much of the software will be shared over a wide range of models, and their support is generally good.