I've been using fast-drying top coats for a year now, and I've used 3 different ones. They are all very fast drying, but I had a few issues I'd like to share with you right now.
Sally Hansen Insta-Dri
This is the first quick-drying top coat I've ever tried. It dries within a minute, and in about 20 minutes, it's non-dentable. I've been mainly using this over Konad, because as everybody knows, Konad tends to smear. This top coat is extremely runny, like water. I don't need to put a thick globe on my nail, all I need to do is swipe it across the nail with a regular amount on, and it goes on without smearing. The shine is nice and I only experience minor tipwear after day 3. Remember my last manicure, the lilac one? It's still on, no chipping, no fading. Only some tipwear, which is acceptable.
The brush is wide and soft, it doesn't pull nailpolish or stamped images. What I don't like about it is the consistency. It's really, really runny. From heaving out of the bottle to applying it on my nail, it drips. And because of it being so runny, there is always too much amount on the brush, and you have to swipe carefully. (Remember, too much swiping - likely to smear the image.)
Oh by the way, when I reach the half of the bottle, it becomes gloopy and too thick. But I managed to control it with polish thinner, now I can use almost the whole bottle.
But I really like it, it's handy and I try to keep a bottle around.
Positive: Doesn't smear, nice brush, dries very fast, shiny, protective.
Negative: Too runny, becomes gloopy after a while.
Sally Hansen Mega Shine
I had very high hopes for this top coat. First of all, it really lives up it's name. It's extremely shiny, dries very very fast, in 10 seconds or so. It's very protective on the nail surface and provides a shield. It doesn't cause me any chipping, any tipwear for a reasonable time, nor any nail polish coming off in large chunks. I really like the look of it on my nails.
There are two problems with this polish. Actually three, but the third one is a common issue of all fast-drying top coats. First of all, the brush is weird. It's synthetic, like made of fiber, and it smears the design crazy. I can't use it with Konad, it bleeds on the nail and looks horrible. There are 2 ways to make it work with Konad, you can either use a regular, natural haired, soft brush to apply, or you can use it on another non-smearing top coat to seal.
Secondly, it shrinks. On the sides, it's clearly visible that it shrinks, and there is nothing I could do to prevent that. First few weeks the shrinking was not too noticeable, but then it was there and I just couldn't ignore it.
And last but not least, it becomes very gloopy, even gloopier than Insta-Dri. In fact, make it a triple.
And that you can't see the inside of the bottle because of the mirror-like finish, you don't have an idea how much polish is still left. And the stuff they covered the bottle with becomes so thick around the bottleneck, that it caused me too much pain and frustration every time I screwed the cap.
I'd recommend this top coat for a nice shine and it's super fast drying time, but it's only good for the first half of the bottle.
Positive: Dries extremely fast, very shiny, very protective.
Negative: Bad brush & bottle, becomes ridiculously gloopy, shrinks visibly on the nail.
This is the last top coat I've tried, and it's so far the best. Take the good aspects of Insta-Dri and Mega Shine, and you have Mavadry. First of all, it dries really fast. Maybe a bit slower than Mega Shine, but still, very fast. The brush is soft and nice, and I didn't experience any smearing. It's super shiny, looks beautiful on the nail. I can't say anything about the protection, because I was in a bad mood those days and removed my polish far too often. But I remember experiencing some minor chips in the corners when using this top coat, but this may be due to washing/cooking too much those days. I'll update on that aspect when I repurchase.
Other than that, I don't have much to say about it. It also became gloopy the second half, but I managed to use 9/10 of the bottle, and that's saying something.
The label covers the whole side of the bottle so you can't really see what's going on inside, but I thought of turning the bottle sideways and observe from the bottom, and that it's perfectly cylindrical, you can have an idea of the condition of the product inside.
Positive: Dries really fast, very shiny, doesn't become too gloopy, nice brush
Negative: Minor chipping(?), bottle is almost completely covered with a label
I hope this review helps some of you folks out there!