Going to print new printer, is it better then SD/ Mendel, Rostock or ?

I wanted my 3d printer to make parts not to print test parts all day proving that my tension is correct or waiitng on spare parts only to fail on 'real' parts and try again. I have had my SD2 now for a few months and after battling the Y shift issue I finally got some things going last night.

I replaced my X & Y drivers with surestepr and dialed volatile in and definitely more stable and sounded better and more robust. (the buzz of the servos) I adjusted my tension a million times. Here is my test now. With power off and servo still connected I can slide with one finger/hand on the x carriage in the middle and glides smoothly and I can even glide smoothly by pushing on far left or far right of x carriage, That to me is as friction free you can get. But I do realize it is probably too much since I introduced more backlash in the X I think. FOr now I am not worried it appears on smaller 1" dia parts laregr parts or rounds over a few inches all seem accurate and round.

SO after all that I still had shifting and I figure it couldn't by mt steppers anymore so I cleaned my nozzle with just a guitar string and that seemed to work. No more shifting after about 6 prints all night.? is that weird? Maybe it was hanging up on small partial clog and dragging?

SO It runs and sounds good, I do notice after re calibration my banding still more noticeable and maybe with .99 slic4r my top and bottom fill quality is worse lot thinner and more holes on the edges.

I am happy it is running and I want to get back too printing parts for my projects. but I know problems are around the corner. I bet my hot end and then my servos are next. I hear a lot of clunking in the extruder head near the back rod during layer shifts or during long fast x switch directions. I am assuming backlash? Not sure why now I never had it before and belts are tight and setup is fixed?

SO my dilemenia:
1: Anyone have above symptoms and give me any more advice that I havent already done like extruded clunking or fine tuning tension? LOL

2: Otherwise to be safe: I want to build a more reliable printer. This SD2 is very simple and now that i have taken it apart I see the X-Y carriage and frame mounting is a cause for much of the issue. I mean if they drilled the frame wrong or off center all your problems will NEVER go away. LOL And the electronics are overheated and probably quality issues. Not the SD fault but it appears there are better alternatives (which I can swap into the SD2)

A: I am thinking of printing while my SD runs either a Mendel Max or Rostock?

b: Do I just upgrade the x-y setup on the SD to bearings, and better ramps?

I am thinking A is best option since it appears the stronger frame is more rigid and the x-y problems are less on these designs and they easily can handle more speed ( i cannot run over much over 60mm/s on perimeters and rest are 35mm/s and on average I do 35mm/s across the board) otherwise I get drags or miss steps or thing walls and blobs

So for those that have made other printers. Which printer will improve upon my SD problems above and be more reliable? I will spend some money I realize that but I am not looking to drop big money on commercial setup. I am hoping to print my parts, order hardware form amazon, buy good electronics and have a reliable, larger build area, with my own custom tweaks to make it mine and I hope to run perimeters at 100+mm/ss and I know I will have to tweak, firmware etc but I like ot have something that even if I calibrate it every week to run at its best it si something tangible. Like tighten belts till all tight or until they have X slack or backlash. Not just make then loose but not too loose. and each side can be different just do it till it doesn't bind.?

I am thinking the Mendel is cheaper to build and probably more reliable then rostock. The rostock looks wicked but I am thinking the Z axis with 3 legs might have binding issues as well? And the Rostock is probably $$ then the mendel to build.