Congrats on the ARP Solus. I've owned mine 10 years now and I still absolutely love it.
I had mine serviced when I bought it, but it went out of tune on the long journey home from the service shop. Thankfully, it can be tuned quite easily using a small screwdriver through holes in the front panel. The trim pots are quite sensitive though. Amazingly, after 10 years, it still plays pretty much in tune but would probably benefit from another tune now. I haven't experienced any issues with oscillator drift. The oscillators are stable on mine.
The Solus has aggressive leads and big bass and i love experimenting with the FM and Ring Mod. The variable waveforms are nice and the switchable single/multi/auto triggering is a nice feature that the Odyssey doesn't have.
I also love the fact it comes built into a case but doesn't seem to weigh that much. The Solus was half the price of an Odyssey when I bought it. Still seems like a bargain.