I don't own a whole lot of Palm apps...but I can give my opinion on a few.
I use my Palms for live midi sequencing, on the road midi editing of songs and control of midi modules both in the studio and on stage.
I learned from Chad over at MiniMusic that the older palms (m series) are better for controlling midi modules since they run on AAA's and have serial ports with a simple adaptor go directly to midi cable, however they are not so good for editing midi files since most of the useful programs for that didn't come out until the Tungsten series and run on the 5. O.S. (with the exception of the ittymidi app which is all but extinct these days)
Of the MiniMusic apps I have used there is Notepad and Beatpad, both worked well for what they are supposed to do.
In Notepad you can play any type 0 midi file and control all volume and panning for all 16 channels which is useful in a live setting where you have midi files with preset volume and panning data in them and you need to adjust that to optimize your live sound on the fly, change tempo...
Beatpad was also very useful for composing (although it doesn't play pre-existing files) it is basically a sequencing looper in which you can control the beat by editing it in a piano roll with a base line as well, the other good thing about it is you are able to adjust the pitch and speed with some sliders as it is playing allowing you to create some really original compositions it would normally take a DJ a lot more hardware to achieve, a great tool for on the fly techno/house IMHO.
Since then I have moved onto Bohja Loops since it allows you to edit midi files in your Palm, along with a bunch of other stuff involving wav.s and sample loops, but I haven't spent enough time using it in the above scenarios to give it a far review. (*also note you may need SerialFix to run midi modules off some of Tungsten series)
When I first started wanting to use Palms for midi (in my more complicated setting involving modules) it took me MONTHS to research and try to find information about the usable Palms and programs that are still supported and who's companies have not folded....so hopefully this post will be useful to someone googling and save them that hassle-hoff.
If you know anything about midi you know how clunky the sequencers can be,(even the smallest ones Yamaha makes are obtuce and use proprietary formats you have to hook up to computer to convert) so to have the ability to fit something in your shirt pocket that you can create and edit songs with is a heaven sent, and Palm makes it possible, what shocks me is the HUGE gap there is in this market and how many professional muscians I have spoken to that didn't even know this was possible to do on a small device like these Palms.....even tho this technology has been around for over 5 years....
keep shinin
jerm 
This is my review of Bhajis Loops, a midi app and wav. looper app for the Palm platform.
While the functions of Bahjis are well designed and easily executed, you are able to edit midi note events and many other paramters of a midi file one claim that the software writers made simply is not true.
According to their press release it says Bhajis cannot operate external synth modules from your Tungsten because the hardware is not yet available, that's simply not true, with Serial Fix and a simple Serial to Midi adaptor miniMusic made that possible with there app years before Bahjis ever came out.
The writers of Bahjis also claimed as soon as the hardware was available for Palms to be able to control external midi modules they would include support for that in the program....4 years later it's still not there.....
Bahjis is a great program for editing MIDI on Palm platform devices (5.o or greater) but leaves much be desired as far as live midi application for stage use where many devices are controlled via midi program changes, in that application Bahjis is Bogus.
I still have a use for the program *(since in Minimusic app you cannot edit midi files) but it is a pain the but having to close Bahjis after making the changes to the files and then open Mixdemo just to be able to play them through hardware modules.
I shouldn't let Chad over at Minimusic off so easily either, since when I purchased that program back in 2003 it was promissed to eventually have midi editing capability in MixpadPRo version...and the upgrade was supposed to be FREE, but never happened since they moved on to other devices and platforms when the whole iphone thing exploded...leaving us palm users in the dirt.
Summary, Mixpad by Minimusic.com GREAT for playing midi files with Palm devices and using external hardware modules, Bahjis Loops GREAT for editing midi files on Plam devices.
IF only there were ONE program that could do both...
keep shinin
jerm 
