Not yet tried XBA-A2 yet, but after checked the spec and hybrid features from Sony Website, what setup you used with this iem?

Source & quality:
Type of player:
Sound setting:

So far XBA-1 need ClearAudio from Sony player in order to bring out the bass details due to single BA driver setup.

MDR-1A is pretty impressive, but then you need to consider to top up another DAC/AMP for portable players, which is another RM400-RM800 at least, and additional bulky amp to be bundle with your player.

BA iem + player:
=> best portable combo, no AMP needed, but bass lacking(maybe not on hybrid version), However, being portable doesnt mean user is free to move without being tangled and iem is more prone to damage from dropping it.

Wired cans + AMP + player:
=> Worst combo in portability, but Sound Quality guaranteed. Ultimate hassle of being restricted with wires and bulky bundle. Extra cost & weight/space needed on AMP+player bundle.

BT headset + Player/Smartphone:

==> With SBC/AptX, you are paying a premium for a Subpar sound quality, might as well as get a All-in-one walkman headphone (NWZ-WH505), this way you can save a lot unnecessary cost from AMP/external music player. Even with AptX supported, the sound quality loss still quite noticeable. Recommend do not spend more than RM500 for AptX, unless you really a wire-hater.

==> With LDAC, basically you paying a premium price to solve every issues from both iem/wired cans, no wires/AMP needed + no loss on sound quality.(actually quite worth the bucks)
BUT both the player & headphone are required to support LDAC (thats the only limitation).
Currently only MDR-1ABT supports LDAC, and the incoming MDR-100ABN(coming soon), most smartphones support up to AptX only.

After above certain price range, when sound quality is no longer an issue to worry, its all about portability/freedom VS Wired.

Wired headphone definitely quite a hassle for all those thick wire, portability-wise, detachable cable is not really helping other than changing to a better cable...

But the sound quality of the MDR-1A definitely worth the hassle of carrying around if your budget aim for getting only the sound quality part.

Well I am a careless person on small items, so very often I will swing my IEM around accidentally and hit it with other surface, thus I choose to pay more for solving all these hassle.

How good is the LDAC? Comparison of the Sony BT headsets I tested so far.

Sony XB950BT(RM688, RM550 after max discount) => AptX (384kbps)
Sony MDR-10RBT (RM794, RM694 after discount) => AptX (384kbps)
Sony MDR-1ABT (RM1299, RM969 after max discount) => LDAC (990kbps???)

After testing and consider the main factors of being portable VS sound quality:

Device: my A-15 + XBA-1 iem (very neutral and detailed except lacking bass even when DSEE activated)
Setting: Clear Audio ON (to compensate from lacking bass TO Good bass and LIVE details)
Song files: 320kbps/FLAC/other CD rips
Battery life wise:

XB950BT => 20 hours approx., 4 hours charging
MDR-10RBT => 17 hours approx. 2.5 hours charging (pay more for less battery life, seriously?)
MDR-1ABT => 30 hours max approx., 4 hours charging

Weight-wise:

XB950BT => 280g
MDR-10RBT => 210g(the only advantage among 3, but at the significant cost of other features)
MDR-1ABT => 300g

Sound Quality wise: (ClearAudio OFF, DSEE ON)

XBA950BT vs XBA-1 ==> Wins in bass department, but other sound details really lacking, even under AptX setting, which 320kbps MP3 not suppose to suffer any quality loss.

MDR-10RBT vs XBA-1=> slightly better than XB950BT overall performance except bass, but the gap can be ignored.

MDR-1ABT vs XBA-1 =>  LDAC(quality) setting selected, sound details even better than XBA-1 quite a chunk, bass part much much better than previous 2 headset.

My feel on these 3 headset + my iem:

XBA-1 iem => Purchased with RM160, 1 of the best bang for the bucks, its sound quality can literally rival many of those RM400-RM600 headphone, as long as ClearAudio is ON. No AMP needed.

XB950BT => AptX sound quality alone, I wont pay RM550 for this, maybe at most RM475 I might consider for the sake of battery life.

MDR-10RBT => even more expensive than XB950BT and still using AptX? Seriously? imo MDR-10 series is 1 of the most epic fail that not even PHA-1 AMP can save them.

MDR-1ABT => LDAC alone, I would gladly pay over RM700++ for this feature alone, combined with premium build quality and long battery life, RM969 is a well-spent and you got everything about BT headset with 0 quality transfer loss.