Any experience with long-term standard visitor visa?

[chssvi]

Apologies beforehand if this is not the right forum but wasn't quite sure where else to ask.

I've now been living in the UK for almost nine years and have been a UK citizen for a bit over two years (after going through five years of Tier 2 general + one of ILR).

During that time my parents have come to visit three times (my dad came by himself one additional time) and they are planning to come again this year. However, every time they have to apply for a visitor visa, which is only valid for six months. They've never had any trouble with the applications, but it's costly and a bit of a hassle.

Reading the info on standard visitor visas here, it says that it is possible to apply for 2, 5 or 10 year visas.

Given that they'll have to apply again this year, I was wondering if they could eventually apply for a longer visa. Does anyone have any experience with these? Are there any special requirements or risks?

Thanks as always.

[Frontier Mole]

Apply for a two year visa, their travel history will show that they return home and are not an immigration risk. I would not chance a 5 year visa unless they have an extensive history of visiting other ( first world ) countries