The Shures probably come as the stock pair of buds if you're using a Shure wireless system. I used the 215s for one or two hundred gigs. Most of that time I thought I didn't like using IEMs. Then I realized the 215s just kinda blow lol.
I would HIGHLY recommend treating IEMs like a major gear investment, on the order of a good live mic, high-end mouthpiece or whatever. Unless you're already an audiophile with thousands invested in your headphones, they'll mop the floor with whatever you're listening to for pleasure, and they'll make it much easier to hear on the gig (if you've already sunk that bread into a headphone/amp/DAC, etc., you'll want the IEMs anyway lol). It's worth going custom, and it's worth shelling out for a high-end pair if you use them all the time. Even if you have other decent headphones, top of the line IEMs are competitive with even some very high-end headphones... not quite as good for sound stage and airiness, but better obviously for isolation. I shelled out for some good ones last year and they make the gig much more pleasant, plus they're better for casual listening than any of my other headphones and even my studio monitors.
IEMs are essentially headphones... if your sound company already takes care of the wireless end, you're only on the hook for the buds. So, consider that you're saving a grand on the wireless setup and sink it into some good IEMs! Check out the JH Audio line (JH 13 for flat response, Roxanne for bass-head, Angie for solid bass, impressive mids and gorgeous highs, Layla for more of the same if you're richer than God), Noble Audio (the Kaiser 10 has been very well-reviewed consistently), and Ultimate Ears (the UE Reference Monitor is probably the most truly flat offering you'll find).
I wound up going with JH Audio Angies... the adjustable bass of the siren series is convenient, as I like more bass on the gig than I generally do for listening on my own, cuz it helps to hear the pitches more clearly (an area where the 215s are sorely lacking... they just sound like mud when competing with a live band, stage amps and FOH bleed). The Angie delivers a very detailed response with some of the most gorgeous top end I've ever heard. Definitely leans more toward the hi-fi audio end of the spectrum rather than studio reference, but to me as a performer, I feel that delivers more of what's important to me on stage. If I had to mix a band or something using in ears, I'd go for a flatter headphone. Most importantly, since I do use these all the time for listening to music, doing transcription, etc., I wanted something I enjoyed, and the Angies gave me chills when I tried them, moreso than any of the other models.
You can try all these things out in their universal fit versions at Musicians Hearing Solutions in NY. It's a short walk from Penn Station, and Dr. Glick is super cool and fun to deal with. She made the molds for my IEMs and naturally got it right the first time. The customs seal better than the universals, and the bass feels a bit more responsive to me, but the universals give you a good idea of the strengths of each setup.
When it comes down to cost/benefit, consider that your 215s might last a year or two of continuous use, are fairly nondescript and easy to misplace, etc. Once the cable goes bad, you'll wind up buying new ones. Good customs will last. If the cable goes bad, you replace it. You won't forget that you have them on you and they'll do no one else any good. Dropping $1-1.5k on a pair is a lot all at once, but if you use them for 20 years, it's $50 a year for the best mobile listening experience produced by current technology. Compare to $100 every year or two for a mediocre experience and the benefit outweighs the cost easily.
