I found the right hand scale on charts on MT4 really confusing. There were a number of postings about this at the time and I'm saddened to see that it hasn't been improved in MT5.
The scale seems quite arbitary and it is impossible to be able to quickly guage pip distances, which I would have thought was one of the most important aspects of a charting tool. I would like to see an option so that when you click the mouse on the scale and drag it up and down, it moves in increments of say 1,2,5,10,20,50,100 pips - and I mean proper pips, not tenths of a pip.
All we have at the moment is an option under properties to enable a fixed scale. The problem with this is when you move the chart horizontally, you have to go back into properties to adjust it.