Same feels here too. Cassette was kindnof magical and kind of crappy. Well, depending on your machine, potentially very crappy.
One of the better cassette loaders can be found in the 6809 based Tandy CoCo machines. When in the cassette times, I would stress test various machines.
My Atari was bog slow, reading a block at a time, with a pause between... And it was picky and really wanted the dedicated cassette drive. Not recommended at all..
Apples were pretty OK, along with the Tandy machines. The Tandy reader software, whoever wrote it, took full advantage of the nice CPU and 6 bit DAC. I could rest a finger on the tape, slowing it down, then listening to the wow, flutter and speed changes all over the place while the machine recovered. Almost always loaded correctly.
The Apples were not that robust, but worked well enough to not be a big bother.
Both Apple and Tandy machines had good commands for loading and saving right to regions of RAM.
On the Apple, with the spiffy Mini-assembler, it was possible to develop big programs a piece at a time, saving off stuff that worked.
Every so often, it made sense to read a bunch in and save off a nice chunk! Always felt good doing that.
Eventually, you load it all, patch it up, linker style, maybe moving bits around some, and then save it as a completed assembly program.
No source, just the data on the tape and what the mini-assembler would show you when you list memory.
Good times!