Thick towels are not always the easiest to live with
Towel weight is useful information, but the rail and drying conditions deserve equal attention.

Understand what GSM describes
Grams per square metre, often shortened to GSM, describes the weight of a given area of fabric. It is not the weight of the complete towel. A large bath sheet and a small hand towel can have the same GSM while making very different demands on the washing machine and drying rail.
Higher weight often gives a more substantial feel, but it is not a universal score for absorbency or durability. Fibre, yarns, pile construction and finishing all contribute. A lightweight waffle towel and a thick looped towel are different objects, not simply different grades of the same thing.
IKEA's lightweight waffle towel range is one example of a construction designed around low bulk. That does not mean every thin towel behaves identically. Compare the particular items in front of you, including the hems and the way the fabric feels when opened out.
Begin at the towel rail
Measure the space where the towel will hang. If it must remain folded several times over a short rail, a very large thick towel may spend much of its life in a damp bundle. A smaller towel that opens out is sometimes easier to use than a luxurious-looking bath sheet that cannot dry between uses.
Consider the number of people using the room and whether each has a separate hanging space. Buying a heavier set for everyone at once may require a different drying arrangement. The extra demand becomes especially apparent during the monsoon, when outdoor drying is interrupted and windows may stay closed against rain.
Lift a towel of the intended size, not just a shop sample. Imagine carrying a load of them to the washing area. Check whether your machine's guidance allows the quantity you normally wash without overfilling the drum. The dry folded stack can underestimate how awkward the wet load will be.
Choose a manageable mix
You do not have to use one construction everywhere. A substantial bath towel may suit one person while lighter hand towels make sense beside a frequently used basin. Buy for each role and keep enough rotation to replace damp towels with clean, dry ones.
Wash new towels as their labels instruct and avoid using treatments the maker warns against. Judge their performance after normal laundering rather than only their shop softness. When replacing a set, keep a note of both size and fabric weight where supplied. Those two details describe your preference more usefully than the word plush.
Check the shelf as well as the rail
Fold a towel to the shape you normally store and estimate how many will fit on the shelf. A deep pile can make a set surprisingly bulky. If it must be compressed tightly to close a cupboard, removing one towel may disturb the whole stack. Size and construction matter here as much as the weight number.
A bath sheet can also be more cloth than someone wants to handle. Compare its unfolded dimensions with a familiar towel, particularly when buying for another person. Some prefer generous coverage; others prefer something smaller and easier to wrap or carry. If a matching range offers several sizes, there is no need for every household member to choose the largest one.