Cougar,
Not quite accurate.
The 1 year salary for 5 years additional service is an MSBS related bonus. You must be a Sqn Ldr or able to be promoted and you take it within 90 days of the 15 year anniversary of service. As you said it is taxed.
Other options are
1) just stay in the general pool on your standard salary taking whatever bonus (qualification dependant) you get and taking your chances with postings/promotions/airline applications
2) switch to the new flying only scheme (similar but not the same as Spec Aircrew) were you are removed from promotion pool and given a fixed contract (currently at reduced rate) at a defined location.
The road show was a waste of time, with the presenter saying in no uncertain terms DO NOT SWITCH SCHEMES.