I've been using JetPlan since the 1980's (When it was a Lockheed product known as DataPlan) on various types from small turboprop to ultra long-range biz jets and and must say it''s been very reliable for me.
99% of the time flight plans are worked online thru JetPlan.com but in the field when things need to be changed in a hurry there's always someone available at Ops to help over the phone. The rare FP or uplink doesn't make it through the system but not enough to cause a concern.
Once the aircraft biases are tweaked the way you want them you will likely find mission fuel burn within +/- 2% and flight time +/- 1% even on a 5000nm flight. It's a very good product.
Having said that...Jeppesen Int'l Trip Planning service?. There are better options.
Pricing I can't speak to as I don't get the invoice any longer.
Last edited by ksjc; 26th Jun 2014 at 14:32.