You will probably get mixed opinions on this question- but, IMHO- no. If your 19 is working fine and you like it; upgrading with a SAMA will cost less than starting over with a Scout.
However, if you like a bit more PRAT; then maybe the Scout is for you. The Scout allows for a bit more 'air' and punch, but has a slightly smaller presentation (soundstage) than the 19.
If you want to stay with the VPI line, you might consider an Aries (or TNT Jr). These will allow you to upgrade to a longer arm in the future if you feel you need or want that.
If you decide to go with the SAMA- don't wait too long. VPI has dicontinued the 19 series, perhaps making the SAMA harder to find.
If it were me, I'd just enjoy the 19 and save my money for when your motor and/or bearing wears out- and enjoy the tunes in the meantime.
best,
WEEZ