I'm sure the VP9 is an amazing gun. But when I decided to take the plunge from wood and steel into polymer, I handled every gun I could get my hands on and shot all that I could. I had my heart set on a S&W MP9. I ended up with an FNS9. I handled the VP9, but was unable to shoot it. It was for sale as a new gun and not available for range rental, same as the FNS9.
The reasons I picked the FNS9 over the VP9 are:
Feel. The FNS9 simply fit my hand better. This is an extremely subjective reason influenced by so many factors that no one gun will likely feel exactly the same for two different people.
Price. The FNS9 was quite a bit cheaper at $400 and some change, versus around $700ish for the VP9. The VP9 was still in the price range I'd decided I was willing to pay ($1,000), but that didn't mean I HAD to spend more.
And this. The ambi controls on the VP9. I immediately disliked the long, thin, stamped metal ambi slide release on the VP9. Seemed a very handy thing to get snagged and bent under stress.
Plus, they are not quite the same size, shape, and placement on both sides. Close, but no cigar.
Now, as feel is highly subjective between different people, it's also subjective between the two different hands most people have, so that may not be an issue.
The mag release on the VP9 is cool, and I can imagine it'd be harder to activate accidentally, and with practice it may be possible to activate intentionally more easily!
But notice the FNS9 has identical size and placement on both sides of the gun for it's ambi controls. This wasn't THE deciding factor for me (that was the feel and way it fit my hand), but it was definitely one of the deciding factors.
I'm sure if you get the VP9, you'll be happy as a pig in slop with it. H&K is legendary for good reasons. It may fit you absolutely PERFECTLY for both hands, and my dislike of the ambi safety may be entirely unnecessary. I've seen excellent reviews for shootability and reliability, but I've never owned one myself. If you really like it, I say go for it!
No safety?
That is one of the drawbacks I have on my M&P 9FS. It is m HD weapon and at night I am scared to keep it chambered.
I've said before and I'll say it again: I've never once heard of an unmodified, properly maintained gun in good repair firing randomly while unattended. While being mishandled, yes, but never while no one's hands were on it. Except if it's been stored and then subjected to extreme heat such as a house fire. I've heard of malfunctions in such, but never a random discharge under the above conditions.
I've never personally heard of damaged and neglected guns going off at random while unattended. Going off while being handled though, yes.
If a safetyless gun makes you nervous, I suggest you practice with it as much as possible. If you simply can't bring yourself to fully trust it, I suggest getting one with a safety for your own peace of mind. No one should have a need to be nervous of their own gun, that can actually lead to a negligent discharge rather than preventing one. But if anything, it's actually safer sitting in the night stand drawer chambered, instead of chambered while you're handling it. Read above and take this from it: 100% of negligent discharges are negligent discharges because of user error.
If it makes you nervous because you have small children or are prone to fumbling around nearby it in the dark, may be a great idea to educate the kids (if old enough), or store it somewhere else. If you're scared you'll pick it up half asleep to investigate a bump in the night and shoot yourself in the foot on your way to the kitchen, that's where practice will help.
My mom carried her M&P40 safetyless with an empty chamber for quite a while. Not because she didn't trust the gun, but because she didn't trust HERSELF and her level of experience. Now that she's got more experience, the only time the chamber is empty is when she's shot until empty or when she's cleaning it.
If it's another concern, I, and I'm sure many others here, would be more than willing to offer more advice.