Xbox ram upgrade worth it? and many more questions :P

[Layer01]

Hi all
i am this close --->  <----- to starting my cab (with an xbox inside) but i have a few questions first.
one i am of two minds as to wether to get a pre-modded Xbox of the net or buy a second hand one and do it myself, downside being its second hand more chance for error if i mod it myself and i dont know how to upgread the ram.  if i was to go with the premodded option i'd get the DreamX from http://www.upgrade123.com/catalog/product_info.php?products_id=95
a pre modded xbox with a 200gig HHD and a ram upgrade form 64 to 128, that and the fact thats its pre done, so no risk of blowing myself or my xbox up lol but then they also use some "no name" media chip? would this end up sucking big time in the long run maybe (unlike say an executer 3)?

any thoughts on that subject?
my main issues are has anyone used an xbox with more ram, and if so does this have a positive effect on games (more specificaly ROMS)?

second i was going to get the x-arcade but after reading so many bad things about it in these forums i decided to insead build my own cp. which is cool caue now i can go for a 4 player set up but the controler hacks seem to all have the down side of not haveing analogue support (or so i read) so i was thinking it'd be possible to get two of the "soon-to-be-released" X-arcade  encoders thus giving me a 4p set up (2 p per encoder)? am i right in thining this would work or am i missing some vital thing?

also any info/experiences from people who have a similar set up would be awesome

Cheers
Layer01

[clanggedin]

If really want to play some of the newer games that are on MAME then you'll definately need the RAM upgrade, but if you would rather play the XBOX version of them, then don't waste your money on upgrading the RAM.

[DYNAGOD]

youll see an increse in controller resposne in games such as halo 1 and  2 and other CPU intensive games..
your essentially giving the processor a bigger buffer.