I have a filament (FDM) printer. It's ok, as long as you design within it's parameters.
I used to have access to a $65000 dollar Envisontec resin printer.
The difference between resin and FDM is an entire world apart. Steve's Photon does work comparable to the Envisiontec, just on a smaller scale. He sent me some sample parts that are on par with what I printed on the expensive machine.
3D printing is easy. Designing for printing is the challenging part. As Steve mentioned, printing from someone else's models can be an experience if it needs to be resized. The software can be challenging too. There is design software, optimization software, and slicing software. I use Alibre Design for designing, and a ton of software for optimization - Magics online software is really good; NetFabb, Meshlab, and Meshmixer all have things they do really well. Slicing software is often printer dependent these days; Envisiontec had their own RP software and a version of Magics that did slicing and supporting. Resin printing pretty much requires supports and the support generation can really make or break (literally even) a print, as can part orientation; what is "obviously" the right orientation to print sometimes isn't. Sometimes it takes some experimentation.
From a design standpoint, something that really helps is making sure your part height (and feature height) is a multiple of your layer height. Otherwise, the slicing software will often just "wing it". With FDM, it is also important to get your wire sizes (wall and feature thicknesses) set to a dimension the software recognizes. With a .2mm nozzle, Slic3r often will just totally omit a .2mm feature, unless it is drawn at, say, .25mm. Previewing is helpful.
FDM slicing generates CNC G-code. I have files for my Monoprice Mini that are almost 500,000 lines of G-code. Resin printer slicing software generates an image file for each layer. With a 100 micron layer thickness, each layer is .1mm (.004"), That means a 10mm tall part generates 100 images. A 100mm part produces 1000 layers. G-code can be manually manipulated (if needed, for whatever reason). Resin printing is wholly dependent on the images the software generates.
An FDM printer can produce good results, but there are a lot of variables to take into account. The resin printers produce better results with less post-processing work. Resin is expensive (Envisiontec resin is $250+ per kilogram) while filament is cheap ($20~ish per kilogram).
I plan to add a resin printer to my arsenal next year, but I will still probably turn to my Monoprice FDM for prototyping during the design stages because it is faster and cheaper. The FDM printer has served me well, but resin produces better results right out of the machine - a lot less post-processing work needs to be done. For the time being, if I need a higher quality part than the Monoprice can produce, I use it for prototyping and have Shapeways produce the final product.
I would hope the home resin machines get bigger soon. They basically use cell phone screens with a UV backlight for curing the resin. Maybe at some point in the near future, someone will step up to using a 7" or 10" tablet screen to make a larger machine at a reasonable price. That would make printing bodies a very real possibility.