Which of these two do you like and why?
Depends on how complex i want the part to be. A curved part would look better as a mesh, since it would be smoother. A normal part is good for flat areas plus it doesnt require importing anything.
Both because they can both be useful in many ways. Meshes are useful for complex structures, they can be used for many decorations to light up the place. Parts can be used to build the map/structures, they are easy to learn and are easy to access to. Both are necessary in game development.
It really depends, but generally Blender meshes.
IMO both are better meshes would be a good option, you should tend to use meshes for more complexed models that could be made in a software, you should use meshes for more detailed models, such as for making (swords - guns - cars ect). From what I heard meshes take a while to load in, consider using a variety of both options including parts and meshes.
I would suggest using meshes for more higher details, however, both options are useful in all sorts of things use parts for more simple methods and meshes when they are needed in your case. There are a few similar threads to your question regarding the use of meshes vs parts:
I like using parts more. In the base of it, it’s more of an apples and orange type of situation, you can go with one or the other. The key here, however, is the finer details and what you need. Context essentially matters for that case, along with what you’re willing to settle for. For me, when it comes to some specific thing that I need that is difficult to recreate with parts alone, I’ll settle for alternative. Personally, I’ll go out of my way to try every sort of negate-union trick I know because there is some level of challenge there I enjoy. Don’t let that decide how you build though for certain situations, though.
Blender is best at creating smaller more detailed models like a car, but if your making something like a usable building you should probably use studio
It depends on your choice of architecture.
If you are going for low poly builds then blender or cinema 4d is the route to go down however if you’re a builder that places emphasis on details then roblox studio is a more viable route.
Vehicles and weapons are also best created in blender. If you can hybrid between the two then thats great since you can mix and match different areas of building/modelling.
To be honest, that’s a hard question.
Parts
Parts are good for bigger structures with less detail and without curves or other smooth stuff. Though you could work with plugins like Gap Fill, but your result might not be as good as with blender. Also, working with a lot of parts reduces performance, for example on older (mobile) devices.
Meshes
Meshes are better for very small details or to replace unions, also to make curves n’ smooth parts like I said above. The problem about them is, that they have a trashy hitbox when they’re big and complex. For example, I’ve modelled a ship once in blender and inserted it in studio. The result was a very bad hitbox, and when I was walking on it I sometimes stood a few studs above the actual floor of the ship. Unions are also known for this problem.
So, at all, you might choose what you like to use. It fully depends on what you want to create.