The obvious advantage to an inside reception is that there will be no weather related problems. The disadvantage is that guests are more confined. There is less space to spread out. Most inside reception venue spaces come with tables and chairs. The venue is more inclusive than an outdoor space.
The inside ceremony space is the traditional ceremony we have all seen in pictures. If you want a religious ceremony, it will most likely be inside. No worries about the weather and you know exactly how much space is needed as the pews or chairs are already there. All you have to do is abide by the policies in place and bring some flowers. Some religious spaces will allow you to use their space even if you are not a member. Check with the site to hear their policies. Always book a religious site before booking your reception venue. It is harder to get on the calendar of a church or synagogue than to find a reception venue.
With an outside ceremony your are at the mercy of the weather so you must have a back up plan. If you luck into a beautiful day, you have all the wonders of nature to add to the beauty of your ceremony. Very little additional decorating will be needed. But you must be the kind of person who can "go with the flow" as you never know what the weather will be until the last minute. If you are going to worry about what might happen for your entire planning time, you need to be in an indoor venue.
I recommend you never opt for a completely outside reception. It sounds lovely but you need some kind of shelter in case a shower blows through. If it is sunny and humid, you must provide shade. Having a picnic reception sounds really fun but you have to be realistic and have a covered space available. I have seen receptions get soaked and the guests forced to sit at tables that were dripping water into their laps. Be prepared! On a beautiful day you have the absolute best of all worlds at an outdoor venue.