Everyone agrees Stealth suits are not useful with their current stats, except for Yme-Loc. No one ever fields them, even Yme-Loc (EUK stats).
However, changing their stats is something Yme-Loc has repeatedly stated was against his design philosophy for an approved list, as approved lists should not be changed in any way which might interfere with their playstyle. And useful teleporters would change Tau playstyle a little, that's pretty uncontested.
Tau fluff indicates that Stealth suits spearhead massive battlesuit assaults, through reckon and prepping, and they do have an important role in Tau armies. However, the Tau list was approved before stealth suits could be properly fleshed out, and now the community has to live with the present stealth suit conundrum.
On the other hand, the Tau list is pretty playable through its other formations, so Stealth suits can be (un)happily left aside. They look good in dioramas though

For what it's worth, as many have stated in the past, 1+ initiative, 6 for 250 sounds about right. The usual counterargument is that Broadsides ^should see an initiative increase also if Stealth suits were improved. And that seems to be a problem for the reasons stated above. Personally, making the Broadside Railgun coincide with its current 40k version and increasing its initiative would be an acceptable and dynamic tradeoff, but here again, change is unlikely.