Well they're both very comparable. Hasegawa has slightly better or finer surface detail and molding and perhaps thinner parts such as wing halves etc... The plastic is slightly harder and crispy then Tamayas which lends itself better to sanding etc... Just slightly though. I've noticed Hasegawa kits generaly have thinner gauge sprue rails compared to most other kits even Tamaya. This lends itself to better detail level during mold process. Overall detail level are about the same, very close. Tamaya kits tend to fit better such as at the wing roots without filling. Some Hasegawas kits require a bit of filling here and there. Tamaya can put out an equivilent quality kit vs a Hasegawa for a cheaper price. Hasegawa kits kit a bit more, betweeen 5-8 dollars more sometimes. However Hasegawa has a much larger selection of variants and they routinely release special versions of their kits with uniq decals and markings.
All Tamaya kits available in Hasegawa also usually have better cockpit detail.
I would say Tamaya is my first choice because of price and cockpit detail (corsair is fantastic) then Hasegawa because of selection and bit better surface detail and plastic depthness).
Dragon-DML-TriMaster kits are like Hasegawa kits in detail and plastic just with slightly worse fitting. Then again, thats why they have model putty. They cost more than Hasegawa but they makes awsome kits and they make variants no other brand makes such as the Ju- series bombers. they make the best Luftwaffe stuff in my opinion. They make a slightly better FW-190 than Tamaya. Monogram ProModeller Ju-88A4 is actually a Dragon-DML kit. Italeri Ta-152 is also actually Dragon-DML kit.
If I cant sell these kits, I'll just be forced to keep them.