The flagship of the EOS fleet and replacement for the blighty EOS 1, the much more refined EOS 1N was introduced in 1994 and discontinued in September 2001, quickly finding a solid favouring by the press and documentary photographers for its speed and robustness.
The 1N's rounded profile and sealed push button controls (with early optional heavy-duty weatherproofing over-seals) was favoured by photojournalists and even bushwalkers/mountaineers working in extreme environments. Photographers with small hands found the EOS 1N without the power drive booster E1 (8x AA batteries) fitted delightfully to hand, making it terrific for streetwise photography. It has the option of using a 2CR5 battery or for high levels of sustained speed and power the optional power drive booster [PDBE-1] — the fixed-mirror 1N RS has this booster permanently attached which gives that model a thumping 10 frames per second top speed, letting you burn a roll of 'Vaudeville Velvia' in about 3 seconds). Many analogists (myself among) power the PDBE1 with lithium batteries. I've shot 340 rolls and the batteries are still in there.
The 1N in good to very good condition can be bought for around AUD$500 body only, or about $700 with PDBE1: you do need to watch how older cameras have been treated. I bought mine off eBay after probity checks and scrutinising the seller thoroughly about condition. Of course, the 1N can withstand quite a banging in active service, but after so long, quite a few of the bodies would be showing heavy wear. Bent internal electronic contacts, damaged top panel display or scratched lengs and even marked mirrors are a common symptom of heavy pro use, ordinarily knocked about willy-nilly in bags, back seats and backpacks without body caps. The interchangeable Command Back E1 with intervalometer, frame numbering etc. is quite rare now.
The longer I've owned my bodies the more appreciative I have become for easily coping with heat, cold dust, dirt and the plain curious (i.e. the Customs Officer who wanted the lens removed to check if narcotics were stashed under the mirror!!

),
The 1N does have ideosyncracies. The "two-fingered hokey-pokey" for setting custom functions in a side 'trapdoor' is a bit tedious when you're in a hurry or working in the dark and require a thorough familiarisation to ensure you don't inadvertently set the self-timer up for 2 seconds when you're about to photograph bub seeing the first light of day! Minor quibbles aside I'd buy another to join the two I already have, if only I could justify the weight!
Some other curious facts:
• The 1N consumes virtually no power over extended Bulb exposures
• 2CR5 batteries last much longer in the 1N than, for instance, the EOS 5
• Being a system camera, otherwise awkward EOS lenses such as the sharp-edged TS-E PC lenses,
will not damage the body like they can on the EOS 5 and other models.
• Power Drive Boosters with the AEL button marked with an asterisk ( * ) can use lithium batteries. Those not so marked will be damaged.
At the end of the day, you'll probably form a noticeably definite affinity with one system over another by interchanging the systems frequently — even if that means buying into and out of a system, until you settle with one you really, really like (this is what I did, from 1979 to 1992 when I finally settled on Canon, having worked through Olympus, Pentax, Minolta, Nikon and finally... ).
I will not say "don't consider anything else". The era of these beautiful flagship cameras from all marques has been consigned to a niche in history. Nikon's F4, F5 ... maybe even the F90x are also worth evaluating. For me, the F401 in 1991 didn't go down well at all.
More info on EOS 1N: http://www.mir.com.my/rb/photography/hardwares/classics/eos/index.htm