This seems to be a fairly contentious issue and I wasn't going to post, but I don't agree (in my personal situation) with the majority here. So here's MY perspective, so take it for what it's worth (nothing).
If you go pistol brace, I agree that the SBA3 is the only viable option. I have one for exactly the reason you said: travel. I run a 8.5" 300 BLK upper, using 220 gr subs (12.1 gr CFE BLK) with the can, and 150 gr soft points for a little longer engagement.
I don't care for the brace. The parts that go over your arm that form what would be the stock are rubber. They do twist and bend under pressure. Training with target transitions is when it's most noticeable, to me. I can feel it collapse and shift and it's unsettling when you're shooting that fast at multiple targets. AZ1182 mentioned about cheek weld, which I agree with but you can train around, but I can't overcome the collapsing rubber. I do tend to keep that rifle in a strangle hold (it's little!!) in a way I don't when I am shooting for precision.
This is the one I would grab in a bad environment, so it gets the most training. Train how you fight, and if there were no ATF, or in lawless situation, you'd put a stock on it, not keep the brace.
So in my fairly useless opinion, SBR for home and training, and as you mentioned, SBA3 for travel. I only use the brace occasionally to keep some familiarity with it. Mostly because I don't travel, only in dire need.