You can run it with 2 speakers. 2 sat/1 sub in stereo mode. However, it is much thiner than the PL-II Music mode which uses all 5.1 speakers.

I assume you are asking to define the easiest to move setup. I put two satellites on two mic stands and put two satellites on the keyboard (I ordered the speaker clips from Yamaha for my T2 $35/ea) and put the center channel on the sub.
Everything for a job except for sub, mic stands, keyboard stand fits in one gym bag.

The Z2300 does not have the same power or speakers of the Z5500. 8" vs. 10" sub.

I think you get more versatility with the Z5500 and can do more jobs before having to pull out the big guns.

I know from other posts that you use other speakers for big jobs and you didn't like the TRS-MS02 with Bose. I A/B'd the Z5500 to the TRS-MS02 with Yamaha speakers and I liked the Yamaha better with two speakers. I liked the Z5500 more so with 5.1 speakers and the additional volume was welcomed for the <150 people jobs that I do solo or with a small combo.

I have a Motion Sound KB-100s. A 100 watts stereo amp. I thought the concept was a great idea (stereo and portable). However, I found that the 100 watts just didn't cut it. The 500 watts of the Logitech gets it done.

Hope all this helps.