Birth choices are a very personal thing. I think a lot depends on what makes you comfortable. If being with other people stresses you out during labour it can slow things down, likewise if being on your own freaks you out its not going to help you progress. If you do decide to be on your own then its important to do research and understand any risks. Its a good idea to have a back up plan or know what to do when/if things get too much too fast.
Personally I visited a couple of hospitals close to me and was totally freaked out by them. They have high levels of intervention, c-section, episiotomy etc and didn't seem that intrested in suporting our choices. I didn't feel at all safe in their hands and I think that would have made it hard for me to concentrate on labour which may well have led to a bad experience and interventions. We found another hospital that was much better but decided it was too far away. I find the idea of a freebirth somewhat apealing but was not quite comfortable with not having medical help incase of an emergency. In the end we hired an independent MW for a home birth and she was perfect. She has a lot of experience and was suportive of our choices. She was there when we needed but was good at giving us space. She even left the house for a while after she first arrived and went to have a snooze in another room later on. If I had wanted her to take a more active part I think she would have been good with that too. My husband was with me during most of the labour and it was nice to have someone to do things like rub my back and get me water etc when I wanted. Around the time of transition I just wanted to be left in peace and although the MW and my husband were around they gave me space. Having anyone around that fussed, worried or was pushy during any part of the labour would have driven me crazy. I would prefer not to have a birth partener than have the wrong one.