Lo TRS II
Both the TRS and the TRS-2 are double locking tremolos. There are a few differences:
The TRS is used primarily on Japanese-made guitars, while the TRS-2 is used primarily on Korean (or other) guitars. The PGM30 is an exception (Japanese made with a TRS-2).
The TRS has a larger tremolo block, for better tone and sustain.
The TRS has larger body anchors (stud inserts) and posts (studs), for more stability.
The TRS is made of harder metal than the TRS-2 and stays in tune better.
The arm in the TRS is the screw in type (like the original floyd rose), while the TRS-2 has a collar on the bar that attaches the arm to the bridge (and tends to wobble over time, unlike the Edge).
Both TRS bridges fit into the same rout, so you change out a TRS-2 for the original TRS in a PGM30, JS100, RG320, etc. It does help with tone, as well as tuning.
Avoid these non-Edge Tremolo variations on an Ibanez guitar, as they are typically installed on low end models. The cost difference between making a TRS and Edge equipped guitar is negligible, and fact is that these non-Edge double-locking tremolos are used by Ibanez as a marketing tactic to differentiate between guitar models, such as RG 3xx vs RG4xx vs RG5xx.
To retrofit an Edge/LoPro in a TRS/OFR guitar:
The Edge/LoProEdge will not directly swap into your Ibanez (or other guitar) with a TRS/TRS-II/OFR. A few modifications will typically be required
Tremolo Routing Changes - You will need to increase the length of the cavity (in front of the posts and behind the fine tuners), you might have to widen the cavity and you will have to rout the cavity deeper for full pull-up. This is probably more of a headache than it's worth, since the body finish of an already "cheap" guitar will be effected. Due to manufacturing tollerances, it is sometimes possible to "shoehorn" the Edge/LoPro into the Korean ibanez, but this is the exception, not the rule.
Tremolo Posts - All these locking trems have the same post-to-post measurements. However, the Edge equipped guitars have body anchors that accept the Edge posts which use a set-screw to further stabilize the post to the body anchor. This is a major improvement and something the TRS/OFR guitars lack. It keeps the post from wobbling or moving in the body anchor. The Edge posts do not fit the TRS body anchors. In order to install the improved Edge posts in your TRS equipped guitar, the TRS body anchors will have to be REMOVED (drilled out typically) and replaced with the Edge anchors (glued into the body) before you can use the Edge post with locking set screw.
Best Choice Option - If you have a TRS/TRS-II equipped Ibanez guitar, you can install the Floyd Rose Original/Pro without any modifications to your guitar. That is the easiest and best alternate.
Lo TRS II