The relatively low cost of glass fibre makes it the popular choice for less expensive tents. Its flexibility means a tent bends with the wind to shed gusts rather than stand firm against them. This can be a tad disconcerting when experienced for the first time. However, flexibility rather than strength does mean the overall weight of a tent can be kept down compared with those using steel poles.
None of the tent manufacturers cover broken or split fibreglass poles under warranty, there are simply too many scenarios to account for. Therefore, we always recommend getting a set of Spare Poles to take with you. Just check your tent spec for the correct diameter poles.