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I have that same cheap track saw. Once you adjust the play in the track (there are adjustment knobs to make a tighter fit) I think it's great. He says having not used any other track saw. Lining up can be tricky too as it doesn't cut right along the edge of the track. I offer it up, lower the saw to my cut line, measure the distance from my cut line to the edge of the track then just make sure that is the same along the length of the cut.
If you want to keep costs down, I got this one from screwfix on the back of good reviews from Peter Millard
(who apparently knows his stuff).
The one he reviews there is branded titan, and a different colour, but is the same saw.
I've only used it a little bit, but it's been good to me so far.
Though as @Soul says a good upgrade would be a 2.4m track. I do notice when going from one half of the track to the other. Fine for most things though.