I am a current Legacy 650 Pilot.
Have flown from 145 to the 650 for 10 years.
The new Legacy 650 is the E which if you are going for one I would suggest.
They have updated it with the FANS, CPDLC, Auto throttles and a few other things it really needed.
The Legacy is a work horse as it's derived from an airliner and has relatively good dispatch rate, it's rare that I fine myself grounded due to tech problems.
It has been dubbed the Skoda of the biz jet world, that said the after sales service is good world wide and should you need a part the airliner background and the fact the 135s and 145s are still in service and share most of the parts give them good availability.
The cockpit is roomy and the seats slide back for plenty of leg room on long flights(3900nm range FL140 mmo .80 long range .74/.76 I use we have had 8.5hrs out of it but that is slow.)
The cabin alt is 8100 at FL410 which makes you a bit weary on long flights as I understand others are around 5000.
Its a good bang for your buck plane, that said if someone offered me a 7x job tomorrow you wouldn't see me for dust.
But i've enjoyed flying it.
Let me know if you need more info.