You are definitely right.
The internal filter has its own motor and impeller to suck the water which made it more powerful than the sponge filter.
It can even have spray bar or venturi (to push the air into the tank).
Here is a video of Aquael internal filter just for your viewing.
I like to see the air pushing into the water... at 1:13 (1min 13 sec)
For hang on filter, one of the disadvantage is the water inlet pipe is next to the outlet making it less effective.
Top/overhead filter will be a better choice than the hang on filter.
The inlet is at the opposite side(far away) from the outlet.
The inlet uses a power head to suck the water up. So, it's very powerful.
And it's the easiest to clean compare to all other filters.(except for sponge filter)
But if you have a lid on top of your tank, probably it may not be suitable.
Just some additional sharing for precaution/health issue.
During the cleaning of internal filters, our hands will need to get into the water to remove the internal filters.
Do ensure that your hands do not have any open wound or cut.
I was reading some articles of parasites infection where the parasites get into the person hand through the open wound/cut.
Some parasites can cause serious problems if they get into your body.
Another potential danger(my opinion only) is the biofilm.
Currently, I'm using Bacter AE to promote the fast growth of biofilms in my shrimps tank.
The biofilms is a major food for the shrimps especially the shrimplets that may not have access to the shrimp pellets.
The shrimplets will be hiding among the plants most of the time and they only get to eat the biofilms on the plants or driftwoods.
But recently I read about the danger of biofilms in human disease.
So, just take precaution if your hands need to get inside the tank.
Usually I do the cleaning and maintenance work during the water change when the water level is low.
I will usually wear glove, or if not I will wash my hands very clean before and after the works especially if I need to get my hands into the water.
For your reading if you are interested.
A biofilm is an architectural colony of microorganisms, that is irreversibly associated (not removed by gentle rinsing) with a surface and enclosed in a matrix of primarily polysaccharide material.[1] Biofilm contains microbial cells adherent to one-another and to a static surface (living or...
physio-pedia.com
A biofilm is a community of microbes on a surface that is encased in a polymer coating. Bacteria that grow attached to surfaces rather than floating in a liquid are called sessile. Most bacteria in nature are sessile, and aggregates of sessile bacteria can form biofilms.
www.news-medical.net