Apart from the lack of PWM

You can do a pseudo PWM though.

so "ppwm" then?

PeePee-WM... yes..

I love Sylenth1, IMHO, it sounds great and there's always some new sound to discover in it.

If you're into EDM music, feel free to try:
http://www.designasound.com/soundbank-edm-factory-sylenth-pr esets.php

there's 25 presets free demo too

More filter types. Other synths have, like 10+. Harmor, for example, even has a custom shape filter, a phaser, etc. I think new filters would be the most important update, to move it farther from the 'trancy' or 'Virus-y' character it currently has.

If it ever gets an update, though...

From what I can gather, it's already perfect and you should go make music!

For the quadrillionth time in this thread: No 64bit for Mac users = not perfect.

amen...

So the "hihi" means nothing here?

The saw + ramp + phase modulation method in Sylenth creates sounds along the lines of PWM - however, they lack controllability, in the sense that they spin out of control.

Suppose you have pulsewidth x and you apply positive phase modulation via midi control, an env or LFO, you'll get a change in PW equal to y. Now, do negative movement so you go back to pulsewidth x (a required staple of controllable PWM effects) and you'll find yourself moving not distance y but some other distance, missing x completely. So quickly these discrepancies add up and the phase completely misses and goes "through zero" and wraps from 0 to 100% pulsewidth.

I think this effect even changes depending on what key you play.

Other synths that also require you to "fake" PWM, such as Corona, are able to pull off controllable PWM via the subtractive saw method, so I don't really know what gives, but as a lover of PWM and controlled PWM effects that was a big turnoff of an otherwise pretty great synth.

The combination of the detune ratios and the full spectrum oscillators lead to a harsh, metallic sound that I don't quite like. This could be the softsynth Fatboy Slim's talking about.

So, what's your favourite PWM implementation [in any instrument] and why?

Pretty much anything that can do it correctly and go right down to a tiny 1% impulse (and back) without aliasing or going all frizzy in the highs. Diva, Zebra2, ABL2 (does a good Roland-style pulse), Linplug Alpha (PWM distortion on any waveform, including multiple cycles), really any good modern VA. Points have to go to Sidizer for getting that C-64 flavour of PWM down very evocatively.

EDIT: Regarding the "why" in general - for me PWM is more than just a way to create detune effects, I like to use PWM as a sound design tool by assigning it in the same way you'd assign a filter. Incomplete PWM implimentations really annoy me - i.e. synths where you have PWM amount and rate, and can't set a start offset (i.e. all modulation happens around 50%). The outer limits of PWM, around the narrowest pulses, is where all the good stuff is, the phasey morphey nasal waves that can cut a drumbreak in half.