Maybe it's not the best virtual instrument for long convolving pads, but their oscillators and filters has enough thickness to fit it's sound quality among some analog machines.
I use it for basses and leads, and sometimes for a soft analog pad, but it is the king of bass sounds for some electronic styles. The envelopes fast response and also a faster filter than most around the net (free & commercial) will open you a door to get punchy sounds with only one oscillator... but there are two more to thicken the sound. In this point, the resonance may not work as you'd like, in fact doesn't autooscillate easily, but it helps keeping control over the sound... and if autoosc is needed, just push the reso to the top....

To use it you should have some experience with other easier instrument, because it's modulation capabilities are enough complex to get lost when modifying presets to fit a sound within a mix.

And referring to some of the questions about doc, support... I've never needed the documentation, and neither those presets (that are really useful, but just presets), and I've never thought:
"oh, sh** it'd be great to have a thing here to do somthing" or the opposite when I've found a lack.
Maybe its user interface is not the best due to its distribution and because all the knobs are of the same size, but when you get used to it that's not a problem.

It's correct and useful, and like analog machines, you'll have to tweak very fine it's knobs to get the sound that you're looking for (but sure you'll find it).

Polyblit is one of the synths I've used most frequently. Being based mainly on free synths, this is one of the most important and versatile synths in my humble arsenal.
why?
well, to begin with, this is one of the best substractive synths available. and I'm not only referring to free synths.
The thing has got 3 oscillators, every one with all the possible and usual waveforms, and all enroutable to 4 lfos (!), filters, etc
In that way, you are able to create almost every possible sound: pads, basses, strange effects...
It sounds very analogue, and I would compare it to the Polysix.

It may lack onboard effects, and that may make you think sometimes that some sounds are too plain. Add a reverb and maybe a delay and you'll be blown! you'll see it can compete with many of the best soft synths available.

I like the GUi, it's very clear; it's not completely easy to use, since it has a lot of commands and modulation routes, but it's worth the effort.

The presets are many and good, they cover pads, basses, etc

And the price...well that can be tricky. When we talk about synths that cost ehem... 0 euros, we are usually inclined to make allowances. Well, forget about allowances here. This synth is one of those you're amazed they're free. get it, you won't regret it.

Polyblit is one of the synths I've used most frequently. Being based mainly on free synths, this is one of the most important and versatile synths in my humble arsenal.
why?
well, to begin with, this is one of the best substractive synths available. and I'm not only referring to free synths.
The thing has got 3 oscillators, every one with all the possible and usual waveforms, and all enroutable to 4 lfos (!), filters, etc
In that way, you are able to create almost every possible sound: pads, basses, strange effects...
It sounds very analogue, and I would compare it to the Polysix.

It may lack onboard effects, and that may make you think sometimes that some sounds are too plain. Add a reverb and maybe a delay and you'll be blown! you'll see it can compete with many of the best soft synths available.

I like the GUi, it's very clear; it's not completely easy to use, since it has a lot of commands and modulation routes, but it's worth the effort.

The presets are many and good, they cover pads, basses, etc

And the price...well that can be tricky. When we talk about synths that cost ehem... 0 euros, we are usually inclined to make allowances. Well, forget about allowances here. This synth is one of those you're amazed they're free. get it, you won't regret it.

This is currently one of the best freeware VA's out there. Great sounds and very flexible modulation routing. I do have some minor technical problems with it in Sonar, even with the 1.0.0.3 update, I hope these get worked out. But sonically it does not disappoint. If you haven't tried it out what are you waiting for? It's great for your pads and leads, especially. Kind of hard to figure out offhand how the filter routing works, I've had to hit the manual a few times on that one; what it looks like it does isn't what it sounds like it's doing. Still this thing is great to have in your arsenal.

This is my first review but what better synth is there to do one on that this great polyphonic synth! The fact that it's free is criminal considering some of the wicked sounds you can get out of it. Not that i'm complaining though...I've been using this synth for a while now and i'm glad to see it has been updated and that Andreas Ersson is keeping up the good work. Here are some of the features I like best about it:

a) Wide range of sounds, from deep basses to light string like sounds...

b) Lot's of control (3 Oscillators, pwm, two mixers etc etc) so you can tweak it to the max.

c) A distinctive character. I find it has a distinct feel whereas many synths that get released do not, and I feel that they should.

d) Lots of presets (It has a lot more than Iblit) that are a good starting point.

e) It hasn't crashed me yet (touch wood) so it's solid as a rock (but thats using Orion so I don't know about Cubase/Sonic users etc).

That's the main things and I have few qualms about it other than that I find the skin a bit uninspiring and it's not that well documented as far as I can see ...Also I don't like the direction you move the mouse to change the values (I prefer up/down not side to side). Apart from that It does the biz...spot on from Ers.