"A lot of the smaller ones aren't members and I think you just lack that backstop should something go wrong," he says.
Consumers should also be wary of contracts as the market for ISPs is constantly changing.
"If you're locked into a three-year contract, you're not going to be able to take advantage of the new thing which comes out next month."
Data limitsYour internet usage habits will determine the amount of data you need. Myriad plans are on offer with prices set for differing levels of data usage.
For those with minimal usage, a cheap dial-up option should suffice, however the connection can be frustratingly slow.
For consumers who use their connection daily, a spectrum of data parcels are on offer - ranging from 2GB a month to 500GB, and "unlimited" parcels are becoming more popular.
Basic phone and broadband internet packages can range from about $50 to $80, depending on the required monthly data parcel.
Internet-only packages are also available and can range from $10 a month for dial-up to broadband packages starting at about $30 a month.
The number of internet subscribers with data caps of 50GB or more increased by almost 800 per cent last year, according to Statistics NZ.
What if you exceed your limit?Depending on your contract, you will either be "throttled" to dial-up connection speeds, or charged a higher per-gigabyte rate when you exceed your allocated data.
Brislen says some ISPs send a "nice email" offering another data parcel while other companies will automatically place you on a casual, high rate.
It pays to check when signing up which option you have agreed to. If you're constantly going over your allowance, getting a higher data cap may be a better option.
Where to go to for helpCustomers who sign up to an ISP affiliated with the TDR can use the service to resolve complaints.
The free scheme covers complaints including customer service, data and billing issues and is available to consumers six weeks after they have complained to their provider - as long as the complaint involves less than $15,000.
The TDR makes an independent decision and can instruct the ISP to pay compensation.
However, if the consumer doesn't agree with the decision, the dispute is closed. The customer can then pursue action through the courts or Disputes Tribunal.
Who comes most recommendedA recent survey by Consumer NZ ranked 16 ISPs on their in-home set up, phone help (billing and technical), online help, connection and speed.
Inspire, Actrix and PlaNet took out the top three spots respectively, with "the big three" - TelstraClear, Vodafone and Telecom languishing halfway down the performance board.
Slingshot, Compass and Woosh occupied the bottom three spots in the survey.