Peter123 has posted a review of the A2S IEM on Head-Fi. It is a hybrid single BA with a 10mm dynamic driver. Included in the review are a few comparisons with other Chinese IEMs including the original A2 (which I own and use frequently). From the review it appears that the A2S is a marked improvement over the original A2, especially in the mids.
Pros: Excellent build quality, easy to drive and fit, non-fatigueing and easy to enjoy siganture
Cons: Slightly soft bass, not the greatest soundstage width
Review of A2S
Paulpark222 has a review of the Primacy ($299) on Head-Fi. This is a hybrid 2-BA 1-dynamic driver IEM. Apparently, it is similar to the Easy LZ A3 ($169) which has an identical driver configuration.
Pros: Sounds natural, smooth and punchy bass, no harshness, great balance
Cons: slightly trimmed high-trebles
Review of the Primacy
Antihippy has posted a review of the Aurisonics Harmony. It is a dual BA with one dynamic configuration. Priced at around $400.
Pros: Great high and low extension, natural sounding mids, bass impact, soundstage and imaging
Cons: Minor driver flex (improved with use/tips), finicky fit, tip/insertion dependant
For a similar configuration you may want to investigate the Easy LZ A2. It has the same configuration and I can attest that it is a very nice IEM. Also, it is currently selling on Amazon for for $115. HisoundFi has a review of the A2 on Head-Fi.
Hisoundfi posted a review on Head-Fi of the LZ-A2 hybrid IEM. I’ve posted reviews of hybrids previous but this IEM is under $100 with free shipping. Hisoundfi believes the A2 is comparable to IEMs many times it’s $100 sale price.
LZ-A2 hybrid review