I'm not sure what you mean by Apple Lossless is not a native format to the Squeezebox.
Check the Slimserver website:
http://wiki.slimdevices.com/index.php/CodecComparison
From the ALAC entry a shade over halfway down the page:
"- Must be transcoded (automatically) to play on SlimServer"
I had to install the Apple codec on my Squeezecenter in order to play any AAC/ALAC tracks.
I understand your enthusiasm for the Transporter. If I had spare cash to throw at my system I'd probably do the same. I did try it under their 30 day home trial. Sure, they took it back without trouble when I returned it but it is still a hassle to bring it in, return it and tie your credit card up for a couple of months.
OTOH, of the two things I suggested, one he should be doing anyway (double checking file streaming settings) no matter which machine he ends up with and the other might take an hour of time to settle the issue one way or the other.