Some important considerations:
Are you planning to use this machine for a. occasional use (hobby, entry level, maintenance shop), b. mid level production (welding shop, small manufacturer, not more than 1 shift on average), c. high production....need parts produced 2 or 3 shifts...(must have minimal downtime, cut to cut cycle times are important, efficient drawing, nesting and material utilization important)
Also.....cut part accuracy. Many machine manufacturers talk about their machines being more accurate than the plasma torch...but don't get into specifics! In reallity...there are entry level, low duty cycle plasma systems (most air plasma fits in this category) and there are high end industrial high definition class plasma systems that....coupled with a machine that can maintain feedrates and contour accuracy at the same time....can produce parts with great accuracy.
There is a huge price, complexity difference between machines. You can buy a 5 x10 machine with an air plasma (80 Amps) that will cut 1/2" material efficiently for around $16k (with a good quality THC).......and you can buy a 5 x 10 precision cutting machine with an industrail hardened cnc control and high definition class plasma.....for $150k.
They both cut metal....the $150K machine will cut faster, at lower cost per part, with higher reliability, less operator intervention, better cut quality/metalurgy, better cut part accuracy.
I work for Hypertherm (32 years) and have worked with virtually every cutting machine manufacturer at one time or another (worldwide....there are over 100 manufacturers of cnc plasma machines). In my home shop I have a PlasmaCam 4 x4 DHC2 machine (they also have a 5 x 10). It has some great features that suit my hobby needs perfectly (fantastic torch heigh control, easy to learn and use CAD/CAM software)......yet there are others in the entry level machine area that would also have suited my needs...such as Dynatorch, Tracker, TorchMate....and a few others.