[fpc-pascal] Is there some disadvantages using mode Delphi?

[Marcos Douglas B. Santos]

On Sat, Apr 29, 2017 at 5:23 PM, Marco van de Voort <marcov at stack.nl> wrote:
>
> In our previous episode, Marcos Douglas B. Santos said:
> > I would like to write some packages that should work in FPC and Delphi.
> > I know that I will need to use {mode delphi} to do that.
> >
> > My ask is: Is there some disadvantages using this mode?
> >
> > I mean, is there something that we only can do in mode objfpc but not in
> > mode delphi, or is it just about syntax?
>
> Mostly syntax. Mode objfpc disambiguates a corner case for procedural types
> with an extra @ for assignment of procedural types, and a few other
> tightenings.
>
> The proponents of mode objfpc make a big deal out of the differences, but
> IMHO it is mostly nitpicking. And worse unnecesarily incompatible
> nitpicking.

Good to know.
I remembered something right now: Is there some problem when units
mode objfpc have "communication" with units using mode delphi about
Unicode?

If I remember well, PChar and even String is different between these
modes, right? The compiler will convert strings between them or this
is not a problem? Even using LCL?