What's the attraction...?
I have produced all of my pre-2009 transparency work with a Canon EOS 1N+power drive booster E1 and multifunction intervalometer back (1994 purchased, in continuous use until switching to MF in 2009), and a swag of L-series lenses. Really, I never cared much for whatever camera was being trumpeted after the 1N as being "better" (in whatever way perceived or actual) when my photography was already doing well with what I had! Reliability in all environments was a first-call requirement 20+ years ago and the 1N, like the 1V, do not shirk at getting wet, dusty, hot, chilled, sweaty or even dropped (but don't do that often!).
These big pro cameras will benefit from established competency in photography, but they can cause stumbling and confusion in the time needed to establish fluency with their operation, and this will most unlikely be immediate if you are stepping up from a consumer-level camera: the 1-series really do require freewheeling system-setting fluency on-the-go.
My concern has always been in the quality and application of the available lenses, and this is where I believe your thinking and money should be spent. Investing in quality lenses is never cheap, especially Canon's/Nikon's, but it is better than glossing over a heavy (2.4kg abouts), technology-laden camera that only holds the film...
You already know the 1V is a professional-level camera descended form the 1N, with excellent E-TTL flash functionality (especially management of wireless multiflash setups, which so very, very few people make use of) but its metering, besides being clustered centrally, was also directly descended from the EOS 1N but has the same number of modalities and more points (not always a benefit). Doubling-up of top panel push buttons/mode selectors, custom functions and the modus operandi of the power drive booster essentially remain close to the same as the 1N. You certainly would not be using either camera with a silly 2CR5 battery, and instead loading up with 8 AA batteries in the power drive booster to really throttle the machine and especially, increase hand-holding flexibility and stability and shooting reliability over the weak and insipid 2CR5 stocks. And yes, a PDBE1 will throttle 10 frames off in a second (with a fast L-series lens matched to it), just for kicks.
The EOS 3, 30 and 33 were just awful cameras that tried to upstage the 1V. This backfired. The 1V sitting on the top shelf on black velvet, did not need interlopers or impersonators, or silly eye controlled focus (I got to experience this with a stand-in EOS 5 and later EOS 50E and only the 50E impressed in its versatility, as the 5 suffered repeated failure of the mode control dial and back cover latch). Used 1V bodies go for around $550 to $790 here in Australia with power-drive booster E1 attached (as would be expected for serious use). The 1N is about $440 to $600.
From recent discussions, Canon does not appear to service either the 1N or 1V (nor other EOS film bodies) now because parts are no longer available. Independent repairers can easily take up the void, and indeed, the dust removal from my 1N was a 1.5 hour job and $49.50 -- probably 5x that with Canon...
An ordinary, unremarkable summary: buy whatever camera takes your fancy. But put your money and photographic skill into quality lenses.
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