Here is what I have found in regards to the major difference.
The major upgrade for the SE model is the addition of an ergonomic touring seat that makes long days on the water more comfortable and gives you the ability to have a rear-facing rider when towing.
The Sea Doo GTI SE 130 also comes with the addition of a side grip bar and reboarding step to make it easier to climb onto the PWC from in the water. If you enjoy towsports, swimming from your PWC or like riding on the edge, the reboarding step will make getting out of the water smoother.
The 155 engine adds the following.
The GTI SE 155 comes upgraded with a VTS (Variable Trim System) so you can raise or lower the bow of the PWC while in motion. This lets you increase or decrease the amount of bounce the PWC has over waves, as well as increase handling while turning.
The GTI SE 155 alsohas a High-Tech Hub that lets you switch between Touring, Sport and Eco driving modes, as well as monitoring fuel consumption, alerting you not only to how much remains in the vehicle, but also your average fuel consumption.
And going up to the limited adds the following.
The Sea Doo GTI Limited 155 is the top of the line model for the GTI series. It comes with a high-performance electric VTS that you can pre-program to adjust the trim of the PWC to maximize acceleration and increase stability at high speeds.
The GTI Limited 155's HUB has been upgraded with Cruise Control, as well as a fuel gauge that displays time/distance to empty.
The Sea Doo GTI Limited 155 also comes with extra accessories for the personal watercraft, such as a removable dry storage bag, safety kit and a watercraft cover.
In my opinion, unless you specifically want/desire the upgrades that come with the LIMITED version, I would not spend the money on the GTI ski. The GTI is a great ski but is considered an entry level ski. If you are going to spend the money on the LIMITED ski, you might as well step up to the next level as all the LIMITED stuff will pretty much be basic on the next higher ski, such as the GTX.
At a minimum, I would get the GTI SE 130 as it includes a Touring Seat, which is SUPER comfortable and makes it easier to ride the ski, and the reboarding ladder.
And if I could justify it, I would step up to the 155 for two main reasons, it has VTS which is a FANTASTIC option. And the 155 comes with a different cam and MPEM which will give you a decent increase of performance over the 130 but still be very good on fuel, especially as it comes with Touring, Sport and Eco mode...