Need advice: MaxNC or Sherline or other or nothing

Hello. So I am looking for advice on which machine I should purchase.
As you can see from the title of the post, the machines I am
considering are:
MaxNC 15CL2
Sherline 8020 CNC

So I'm probably going to do most of my work in aluminum, but it would
be nice if I could do work in copper/brass/steel, even if I have to
go super slow. I do have access to GibbsCAM, so adapting my toolpaths
for a large number of passes should be fairly easy.

I'll go through my though process here, so if you see anything
glaringly wrong, please let me know... that's why I'm here!

- It seems from what I've read that the sherline machine is built
better, more solidly, and would probably end up being more repetable
and able to work with steel when I need to.
- However, the two major shortcomings of the sherline are the
reduced X travel (only 9" as opposed to 12" on the maxNC), and the
stepper motor drive.
- I can probably live with the reduced X travel, as I am not making
anything that is too huge (yet)... I also have >some< access to a
large FADAL machine... is it realistic that maybe I could fabricate a
new X table and retrofit the machine? I dont really want to have to
do that though, unless I know it'll work nicely.
- I worry about stepper motor drive in the event that I do miss a
step and throw the whole program off. Should this be a realistic
concern? Would the closed loop servos on the MaxNC really deliver a
more reliable operation over these sherline steppers?
- I'd have to set the spindle speed manually on the sherline, and
can't do it with the program... but I dont think thats >too< big a
deal, is it?
- So, like I said before, I have access to GibbsCAM, so software
isn't an issue here. I am pretty good with Linux, so I should be able
to set up EMC with the sherline system without a problem.

With all that being said, I am seeking advice on which machine I
should go with. I am leaning towards the Sherline because I've heard
good things about them, and they are a fair bit cheaper.
I would greatly appreciate any advice or input on this decision....
if you could address any of my worries, that'd be great.

Thanks,
Andrew Pullin