As someone who's been sewing for over 12 years, I can very confidently say that the Cait Sith has much better craftsmanship and material selection than the Sonic plush and has more of a vibe of something a professional plusher would craft.
Blaze
-Head is very clearly lopsided from the promo picture alone. These pictures often showcase the prototype versus the actual mass produced plush and having such a clearly flawed piece pictured to advertise the product is like the distributor going "lol here's your darn cat".
-Her pupils are ironed on and the forehead jewel is glued. These features are absolutely going to get damaged and collect dirt over time if the plush is displayed normally and any attempts to hand wash it will make the damage worse.
-She's made out a cheap generic and vaguely soft flame resistant polyester.
-The fur details are made out a very thing and low quality faux fur. That fur is absolutely going to fall out and get matted over time and washing will again, make the damage worse.
Cait Sith
-The head and body are mostly symmetrical (minus the little pink leg ends) and the promo pictures make it clear as such. It is being photographed and advertised as a premium collectable and inspires confidence that it's been produced as such.
-Cait Sith is mainly constructed out of minky fabric. Minky is the top of the line with plush currently, it's extremely soft, pleasant to look at, and won't get gunked up with age if displayed with proper care.
-All of Cait Sith's parts are very firmly sewn in, even the eyes. I could take a toothbrush to gently surface clean Cait Sith if needed without causing damage.
-My only real complaint with Cait Sith is the ear shape and how close together they are. However giving him heart shaped ears like the minion has would've been rather difficult on a mass produced scaled because of how the ears have the be sewn into the head before the head is turned inside out and sewn into the body. I wouldve just ladder-stitched his head on to avoid that if I was making him, but that's a time consuming hand finishing technique that's not factory friendly.