Merida's heartland has always been bombproof aluminium hardtails. Half a century of frame building experience counts for a lot.
The UK version of the Big Nine and Big Seven 15 have been upgraded to use a sophisticated TFS frame featuring the latest technology:
full internal cable routing for a clean, neat set up,
tapered headtube offering the potential for future upgrades
inboard disc brake mounts protect the brake and maximise stopping power
As much Shimano componentry as possible has been added to complement the modern frame and enhance reliability.
There are a wide range of sizes; Big Nine for taller riders and Big Seven for shorter riders with a healthy overlap between the two.
For riders in the middle, riding style can be taken into account. If you are looking for speed and efficiency choose a Big Nine, if you are looking for agility choose a Big Seven.