Lots of mixed reactions to the patch; it certainly hasn't been a 100% success.
The sim definitely feels smoother than before and overall the performance has improved.
The anti-alaising has also been improved.
All the texture issues with Orbx products seem to have been sorted too.
Also quite a few people (including Kosta) are reporting terrible scenery texture blurring since installing v2.1 - I only fly GA/turbo prop and occasionally tube liner so high speed ground texture loading whilst zipping by in an F22 at 800 feet isn't an issue for me.
However there is a theory that a full clean install is more preferable to just installing the patch - many reporting weird issues have only installed with patch - I opted for a full clean install.
Also LM seem to have reduced the Autogen radius - the FSX style "autogen pop" is back, I wasn't getting that with v2.0, the autogen seemed to fade in more gradually and naturally.
And it looks really poor at night particularly when using Orbx scenery as their 3d night lights are autogen - the immediate area around the plane has ground lights but they cut off far too close and completely ruin night flight immersion (for me anyway)
Also the taxi/runway/night lighting issues with legacy products from Aerosoft, Sim720 and numerous other developers are still present - there hasn't been as great an improvement in the back compatibility with existing FSX addons as I'd hoped.
I completed a flight last night in the Majestic Q400 from Flytampa Vienna to Flytampa Athens then down to Aerosoft Thessaloniki, the vast majority of my sliders to the right with lots of shadows, flying over FTX Global and FTX Vector with FS Global 2010 FTX mesh with REX Direct 2048 clouds and Opus weather and didn't get an OOM and rarely did my FPS drop below 30, couldn't do that in FSX or v2.0 so there does seem to have been an improvement on memory management and VAS usage.
In a nutshell the only elements of P3D 2.1 I'm not stoked about is the too small autogen radius, the back compatibility lighting issues which effect a lot of my airport scenery addons, the lack of Orbx UK FTX regions and airports (thats just a waiting game), no PMDG and no RealAir support.
I'm holding off on any more simming purchases for a while, I'm going to wait a few months and see if there is a trend towards P3D v2 or X-Plane - the future MUST be 64-bit there is no way around it, we will all have to leave FSX eventually.
Patience..........
For those who are interested here is my list of addons that I've installed and run perfectly well with no issues in v2.1
Updated FSUIPC from Pete Dowson <-- life saver!
EZDok camera
Aivlasoft EFB
REX Direct Textures
A2A Cessna 172
Aerosoft Airbus Extended
Aerosoft Twin Otter
PMDG JS4100
Various Carenados - B1900D, Caravan EX HD, SR22, Malibu, TBM850, B200
Qualitywings BAe146/RJ's
Razbam Metroliner
UK2000 Edinburgh, Glasgow, Cumbernauld, Manchester, East Midlands, Bristol and London City (I'm sure the rest will work just haven't installed them yet)
Flytampa Vienna and Athens
Aerosoft Oslo v2 and Thesaloniki
Orbx FTX Ireland and Northern Ireland
FTX Global
FTX Vector
FS Global 2010 FTX Edition mesh