Well now that I've gigged with my onboard wireless, I'm pleased how well it works.
Prior to me putting it into my bass, these were the issues I had (albeit minor)...
Flexible antenna causes noise (fixed by attaching a small rod to the case and the antenna), but it left me with the issue of it sticking out and bumping it into things.
Velcroing the loose end of the unit to my bass left it sticking out a bit and bumping the antenna into things.
Having to shut the unit off between sets to save battery life, and pulling the plug out to save my active bass' preamp battery. The switch on this unit is tiny and hard to tell what position it's in. Though I now have a mute switch on my amp, this process was a pain and if I forgot to mute my bass on the board before turning off the wireless I got this "tornado-like" LOUD hiss.
Where to store my wireless when not in use to keep the antenna protected (fragile little sucker).
Forgetting to pull the wireless out of my bass (it's so small) and putting my bass back in my gig bag with the wireless still attached (which drained the battery on my preamp and put stress on the antenna in the gig bag).
Now none of this is anything extreme, and they were just a bunch of little hassles or annoyances but combined made using my wireless a bit more of a hassle.
Now that I've mounted the transmitter inside the cavity with the antenna velcroed to the back of my bass (outside the cavity) I not only have eliminated all the hassles, it is as easy to use as the flip of a switch (literally).
The range is the same (farther than I ever go anyway), it is noise free, and it is so simple to operate.
I'm loving having an onboard wireless!!! It was very easy to install (once I knew how to wire it up).