I like both. Injection molds/injectors are more money than hand pour molds, many of which you can make yourself with little to no cost. Pyrex cups are $2-$3...
Injection is extemely simple to do. If you can pull back on a plunger and push down on one, you can inject perfect baits every time. I actually bought one from a manufacturer along with molds and was making baits within minutes of opening the box. Really a no brainer. Super fast also.
If you are talking production, it all really depends on the number of molds you have. A guy can out pour an injector if the injector only has a few cavities. Visa versa applies as well.
If you want to do laminates a lot, choose injection unless you have lots of experience hand pouring. Injection takes the guess work away. It does cost more to get that all set up.
If you want to do veins, 3 to 4 color wormss, swimbaits in 3 or more colors or baits with a head color (ie white swim with red head), you have to go to hand pour as you cannot reliably produce (in some cases cannot produce) these without an open pour mold.
Also depends on the baits you want to do. Some things, like thin appendages or flappers, may only be possible with hand injection. Take that into consideration as well.
I think I really like having a mix of both. Gives me the option to run junebug all night long on hand injection molds or I can break out the hand pour molds and get busy on some Aaron's Magic with chartreuse tails also....
Just my opinion though....
Jim