Just a few comments from my Mak_newt research before I bought mine. I looked at the ES mak-newt but it seems to be less featured than a Intes of the same size, basically a budget version of a proper Mak-Newt. It did not seem to have the internal tube baffling that the Intes-Micro and Skywatcher have, and it has a short focal length in comparison which may be good for wide field comet hunting but limits magnification for both visual use and imaging. It does not come with rear plate holes for a fan mount (has a small hole behind the primary but no tapped holes to mount a fan). Also if your considering comparisons with a APO refractor, the size of the ES 6" puts you in a 100-120mm APO refractor comparison area, and those ED APOs have come down in cost considerably over the last year.
Over on Cloudy Nights there is a guy with a collimation problem with his new ES mak-newt, which looks like the secondary is way out of alignment.
http://www.cloudynights.com/topic/50...h-the-trouble/
In summary on the ES, too small, less featured but low cost, would be my view.
As to weight, you can't really get away from it in a Mak-Newt, but it is well balanced (with the primary weighing just alittle more than the corrector plate/secondary assembly). So it sits on a mount nicely without the long moment arm of a long newt. My MN190 weighs a little less than my carbon fibre strut 10" f5 imaging newt, but it sits on the mount better imho.
All of the Mak-Newts will be collimation sensitive, and it helps to have a newt background when checking it and setting it up. The issue they all have is that the secondary is mounted directly on the back of the corrector plate - thus this puts the focuser very close to the end of the tube. On the MN190 the secondary has a small circle on it to aid alignment, just centre the secondary circle with the primary donut and your very close to perfect. I know from following some Cloudy Night threads on the Orion Mak-Newt (no longer in production and an earlier version of the Skywatcher with a larger secondary), that if you follow standard collimation practice (and don't have the secondary spot marked) it can cause all sort of issues. People try to use standard Newt secondary offset numbers from the newt calculators and this messes up collimation on a Mak-Newt. If possible get one with the secondary spotted it makes collimation very easy, and forget using Newt design secondary offsets. Once set they hold collimation very well.
Finally resist the temptation to upgrade the focuser, some CN people have been tearing their hair out trying to fit Moonlight focusers to MN190s and Orions, because there is no adaptor plate for them that allows the necessary adjustment of the focuser towards the front of the tube - result the collimation is way out. Surprisingly there is one for the Intes MN models. Check out the Moonlight Newt focusers and the
Intes MN Upgrade (Model IntesMN-MK) adaptor and you can see how it allows the focuser to slide forward along the tube.
Here are links to some info that show photos of the usual Mak-Newt tube baffling for the Intes and Skywatcher, my view is that if the ES had it they would promote it - and they don't:
http://www.myastroshop.com.au/guides/swdm190.asp
http://www.apm-telescopes.de/en/tele...-delivery.html
Hope this helps.
