Well Tokyo Marui afaik does make really good airsoft guns.
For "value for money" they make horrid guns. Internals only last under their own sub-1J spring, if upgraded, they die quite fast. Plastic externals looks very nice at first but the thin coating wears off and shiny toy-plastic starts to show. Metal parts are decent but nowhere near the top makers.
Then theres the price, for TM price you can pimp out and upgrade a cheaper china-made gun into a everlasting skirmish-monster.