I also think there is a point with dtg were you can get to fast.. as far as the white ink printing goes.. what happens is the cmyk pools if its applied to quickly.. the white needs to gel for a bit.. this is why the one pass (printing white and cmyk at the same time was a flop) the prints are dull... I think this is a limitation to dtg with current ink technology..
i dont think its wise to get much faster than a 1 minute print on the white underbase and that may be pushing it a bit...
this is the 4800 printers claim to fame as far as its bright or qauility image, its my opinion that because the 4800 are such slow printers that it allows the white to dry better giving a perception of a better qauility when in fact its related to print speed..
this was also documented by stichup on the commercial side with the neo flex.. he claims using the three platens and printing white on all three then going back and doing the color over produces better prints then doing a single shirt at a time or single platen.. which many agree.. i guess this was accidentlly discovered by scott fresner when using his blazer express machines with multiple platens...
there is quite a bit to dtg and there limitations as far as print times.. I think any of the diydtg epson formats can be competitive as long as there is a resonable non clog printer for the white... the 1100 has the best chance with its larger drop size/ waiting on 1100 all white results..
otherwise a different format needs to be looked at... (screen printing is not that hard either and my current choice until a white ink can be printed in epsons without clog issues..) If the all white ink can sit in an 1100 for a week without issue ill get excited and build a couple of these dual printer machines...
