I have a 1000 hrs on the ST, all single pilot and mostly on the left seat. I agree with Lingo Dan on the starts, we had problems starting the engines until they found new types of batteries (you need the exact voltage to start these things) and higher quality starter,s then no more problems.
I was doing vertical reference work with them and I am curious about what kind of work you would be doing?
If you end up doing areal work with them like I did (fire fighting, drill move etc) I would suggest you leave the Fly by wire system OFF and the rear stabs in the neutral position and keep it below 100kts the VNE without the system ON if I recall. The system is sensitive and will come off line all the time. Also the SCAS system is sensitive as well, don't rush the controls, the system will fight back. One more thing, always remember to put the SCAS ON before take off, she is a handful without it. I did loose all electrical one day while flying and had to do a precautionary landing on skids with all systems off and it was a challenge.
Once you know and understand this machine they are a love to fly and YES I wish Bell made a mark 2 as well. The 525 might be it though.
JD