So....I'm considering starting Negima....

[OpMegs]

However, there are a handful of concerns that I have, which I care to get an informed opinion on.

Concern #1: How to obtain/read it

As quoted from TV Tropes...

Lost In Translation (The Del Rey English adaptation of the original manga is distressingly
spotty. In particular, the first volume (and to a lesser extent the next three) seems to have been a misguided attempt at a Gag Dub. Volume 5 reads
like too much effort was spent on making it sound colloquial and not enough on making sure the translation made sense,
and volumes 20 and 21 are just lazy - even the Latin got ruined. Things are looking up, though, with the Nibley sisters
translating from volume 22 onwards...)

Between that and the Long Runner status preventing the anime adaption from matching up to half the examples on TV Tropes that have intrigued me
enough to actually look at this seriously, I'm a bit concerned. However, I'm aware that the (again, oft-linked from TV Tropes) manga is available
translated on several online fan-translation sites. Any recommendations?

Concern #2: Yes, but is it as bad as Rumiko Takahashi?

Now understand, I mean no disrespect to the lady herself, but All Entertainment Being Subjective, two of said writer/artist's most famous long runners
bore me to tears(Inuyasha, Ranma) due to stagnant characters that only get to develop and grow notably in fanfic.
Similarly, another popular long runner(Bleach) similarly lost me due to the fact that...um...well, it's DBZ but better written. Shonen's not my thing,
so the fancy upgrades and such have to have a suitably gripping plot to hold me there. Given that, if anything, Negima's fanservice is its massively hyped
author appeal point rather than Constant Constipation Competitions. I can deal with that. But I would like some plot with my fanservice, hopefully.

Concern #3: KEKEKEKEKEKE, ARCHIVE RUSH.

As noted above, Long Runners need to really hook me to keep my attention, but suitably well written ones can (Your Mileage May Vary, but I finished the
archives of Schlock Mercenary and Megatokyo in a couple days each to catch up to present) defer my typical reaction of "I'll never catch up with
it!" However, if the above two concerns are alleviated, then this one's not really a big worry.

Concern #4: Scorecards, Players, and The Interaction Thereof

This is a really minor consideration, but Negima has....a reputation for a massive cast which must be kept straight. However, neither the Nanoha-verse nor the
extended cast of Fred Perry's Gold Digger have been able to make me throw up my hands and go "that's it! No more!", so unless Negima manages
to outdo those two....

So, all in all, for ye of the informed opinions, what say ye?
---
"Oh, silver blade, forged in the depths of the beyond. Heed my summons and purge those who stand in my way. Lay
waste."

[Bob Schroeck]

Concern #1 I won't really address. I do both -- I read the fanslations as they come out, and I buy the manga as it is released in the US.

Concern #2: It is in no wise like Takahashi. It is, in my extremely limited experience, also not much like DBZ. It is strongly character-driven, yet not without a rather substantial myth arc driving the entire series so yes, it has considerable plot.

Concern #3 is something I can't really address as I started at the beginning when it was beginning.

Concern #4: Don't panic. The characters are sufficiently differentiated that within a volume or two you'll be wondering why you were so worried about keeping track of them all. Even if the core cast approaches thirty to forty members, depending on how you rank individual importance.
-- Bob
---------
Then the horns kicked in...
...and my shoes began to squeak.

[ordnance11]

Akamatsu managed to do a shonen series in the guise of a harem series (which was his intention). There is a great deal of character growth in the core
cast...even if it's 30 to 40 of them. You will be entertained.
__________________
Into terror!,  Into valour!
Charge ahead! No! Never turn
Yes, it's into the fire we fly
And the devil will burn!
- Scarlett Pimpernell

[CrimsonKMR]

I love the Negima manga. My only real complaint with the English translation that Del Ray does is they keep changing the "adaptor". I don't mean
the one who does the Japanese to English translation, but the one who takes that raw translation and turns it into logical English The first couple volumes
were adapted by Peter David (of comic book and Star Trek novel fame) so it has his sense of humor in it... it seems like every 10 or so volumes afterwords it
changes to someone else....

Its still a pretty good story And needs more Nodoka-chan!
There is no coincidence, only necessity....
- Clow Reed

[Acyl]

My exposure to Negima is through the Chuang Yi Publishing translations. Yes, name aside, they do English volumes. Their market is pretty much exclusively Southeast Asia, though. I don't know if you can get them Stateside. Presumably you could through the wonders of mail order, but whether it'd be economically viable is another thing entirely.
The per-volume cost for Chuang Yi books is very cheap by American standards, to match the price point for Southeast Asian markets. But that's in Asia. Once you add shipping, that incentive for purchase goes poof for someone outside the region.
Anyway, the thing about Chuang Yi English translations...they go for accuracy, not colloquial fluidity. Which means the actual text is perfect English, but comes off as ever so slightly stilted. Is that good or bad? Well, in many ways, it ain't good.
But I personally prefer this to something that's been run through a 'tone' filter though...especially since, as you point out, consistent tone is something the Del Ray version doesn't have. If it means dealing with dialogue that isn't 100% 'natural' sounding, I'll take that, rather than gambling on a given translator's definition of 'natural'. Which is always debatable.
With regards to keeping the cast straight...it's really not difficult. The fact the manga uses the reoccuring device of Negi's classroom seating chart, with pictures, makes it easy to remember who his students are, at least. It's a pretty cool device since, as the series progresses, the copy of the seating chart that's printed in the manga volumes gains handwritten annotations.
However, well...I gave up reading Negima precisely because it got too long, so I can't really help you there. I thought it was pretty cool, but it didn't grab and hold my interest enough for me to keep buying the volumes.
That said, I have the same issue with Bleach and Naruto. Apparently I don't have it in me to stick with the long stuff. So take that for what it's worth.
-- Acyl