In essence, the Islamic prayer to me is very much solacing and complete. I've never really felt I needed anything else after prayers. There's a term "khushoo'" which basically means that determined focus or concentration in your prayer. Everything that I feel, be it thankful, desperate, scared, etc. when I stand up to pray and I'm in full submission to the One and Only, and I know there is no barrier between Him and I, then by the time I finish my prayers it's like I've left all of my worries in His hands. I feel so grateful and blessed in having the full trust in Allah with my future, present, and past. When you prostrate, you can supplicate for anything you want or just give thanks. There is just something different about putting your head on the ground and knowing Allah is closer, it's very reflective.
When I see someone else praying, I see such beauty in it because as an onlooker, I have no idea what this person is going through or what they're asking for, it's like it's a secret between Him and His creator, and no one can destroy that connection. So imagine having such a connection 5 times a day. The crazy thing is it's in different times during the day. In the early morning right before the crack of dawn, you feel as if the whole world is quiet and there you are awake only for the purpose of connecting with God and submitting to him, and during the daytime you stop in the middle of the hustle and bustle of the world again to make this connection, and before you go to bed after your long day you are able to get everything off of your mind and KNOW that Allah understand everything you've been through. But connecting with God doesn't stop at prayers, there's also du'a (or supplicating), and saying particular phrases (such as astughfirallah-May Allah forgive me, Allahu Akbar-God is Great, etc.), and tere's different kinds of sunnah prayers as well such as tahajjud (prayed in the last 3rd of the night) or istikhara (when you can't decide between two permissible things) for example. You connect with God when you want to correct something or do a good deed even when you don't really feel like it, or even when you take the step to improve yourself as a human being. If you feel like you want more than that, then there's nothing wrong with praying extra sunnah prayers at the appropriate times, but we can't spend our entire day in worship because our body has rights over us (it would be very tiring). Instead we strengthen ourselves in other parts of our religion such as reciting and memorizing Quran (which enhances prayer), learning more about the religion, fasting, helping others, paying charity, etc. but I'm sure once you see what 5 prayers entail and how much you can put into it, you'll feel that it's enough
In regards to meditation, I'm only speaking from opinion not from religious knowledge about the topic, but I don't think it's wrong to meditate as a way to just relax and reflect, otherwise in Islam, prayer is our first place of "refuge" so to speak. So prayers shouldn't be replaced or even equated with meditation. Whenever I'm in a very beautiful natural setting, I like to sit and reflect, but I also say words of praise to keep in touch with Allah and acknowledging His creations of this world. When facing tribulations or even great happiness, I personally can't really replace the power of prayers with anything else.
