Speaking personally, I haven't found a 3 in 1 device that works for all of my needs at once. I have yet to find something that is great to pack with that I can also pee with. The STP aspect is what most guys tend to have issues with - I do not recommend getting an expensive one until you know what will and won't work with your anatomy or what style of STP is a good fit for you.
I have a Peecock Gen3. Great for packing, looks good, good for sex, can't pee out of it. I just can't form a good enough seal with it to prevent leaks.
I have a Number One STP. Can't pack well with it, not really a stand-alone packing device so far as I can tell, no option to use it for sex, but I can definitely pee out of it.
I have a few different Mr. Limpy's. Two for packing (I rotate), and one that I've made into an STP with parts that I know work for me. Packs great, looks so-so, can't have sex with it, but I can pee out of it.
I think everybody does a bit of experimentation before they find what works best and what they need out of it. I just don't think it's a good idea to jump into the high end market blindly.