Likewise I've been fancying buying a TIG for a while, but they are rather pricey. I've used them in the past (I worked for BOC back in the day, developing shielding gases).
Pulse is worth it if you are going to be welding thin (<2mm) sections, helps stop melting holes in things and gives you more control, HF start is also very useful.
If you get good at TIG (it is a skill), then I would think you would only use MIG for quick jobs.
SIP are fairly budget, but OK.
Dunno about Chinese jobs, I'd be wary.
Hope that helps
Jeff