TromboneChat

What have you found is the best hand-held portable recorder for recording practice/lessons/4tets, etc.
Zoom H6? TascamDR-40? use an external mic? which one is best??

A Shure MV-88 plugged into an iPhone/iPad works pretty well.

Unless you're recording for something serious like an audition, your phone or a Zoom H2 will get you 99 percent of the way there.

The Zoom H6 is great, but realistically, an H4n or H2 would be more that enough for reference. In my opinion the H4n is the best bang for buck and it allows you to use external mics at some point without having to spend as much as an H6.

I use a Tascam DR-05. One of my favorite features on it is the splitting of a file. It is easy and does the operation quickly. So, I just press record and let it record the entire practice or concert. Then later, as I listen to it, I split it into individual files per song. Files are stored on an SD card, so transfer to computer is simple.

I would personally get one of the models with 2 or 4 XLR inputs. This way you can use the on board mics for basic reference, but you have the option to record with much better mics (and mic placement) for quartets, etc, that are "recording worthy". I think the TASCAM and larger zoom models give you this ability. The newest models can even be used as an audio interface with a PC/laptop, which opens up a new world of options with REAPER and the wide world of plugins.

My basic H2 couldn't do any of that cool stuff, so at a certain point I maxed its potential. Having something that could act like you want, as a basic recorder, but also have the ability to power 2-4 mics by itself, be an audio interface, etc, is something that you might eventually want. The H6 can do all of that.