Although many people believe that travelling in a group led by a tour leader would be more enjoyable, I do strongly disagree with this idea. In my opinion whether you are a night owl who prefer to stay until late at night, or you are a kind of person prefer to have pleasure with your own friends, or you are a kind of interested in having exact and deep knowledge about the place you travel to, traveling in a group led by a tour guide would makes you trouble in a way that you might not be able to make enough pleasure during your trip.
Doubtless, different people have different kinds of attitudes and behaviors. Actually, during a trip one may prefer to attend parties which being held late at night, or prefer to go for a walk at midnight. An example from my own life may shed some light on this issue, I remember last year when I went to Kish, which is a small island in Iran, and I had many difficulties during that trip. Since I like to stay until late at night, I found this trip very boring because most of the exciting parts of the tour programs were started in the mornings and I could not be able to attend them.
We should always remember that travelling with a group of your own friends is more enjoyable since most of the times you have many common interests with each other. Just imagine that you have to bear with a number of noisy people during a visit from a historical site, how this might be annoying for you distracting from the main points that the leader is making. Oppositely, you may prefer to have a lot of fun during the trip and the group that you are traveling with is a kind of silent group in which no one speaks even a word. It is obvious that both situations are unfavorable.
Another side of the coin however is about the amount of knowledge that you wish to gain during your visit from a place. Most of the times traveling in a group led by a tour guide is crowded by too many people and while the leader is describing about important issues you would not be able to pay attention. In this situation it is much better to study about the place you want to visit before the trip and deepen your knowledge about its historical places or its culture. By knowing a lot by yourself you definitely would find the trip more enjoyable.
To put it in a nut shell, from one who has difficulty arrange his time in a group activity or someone who do not enjoy spending time with strangers while traveling, and one whose purpose of traveling is to expand his knowledge, travelling in a group may not be a favorable experience. So does not seem that choose some of your friends and plan to go to the trip with each other and make yourself highly informed about the place you wish to go is a better solution? 
Although  
many
  people
 believe that travelling in a  
group
 led by a  
tour
 leader would be more enjoyable, I do  
strongly
 disagree with this  
idea
. In my opinion whether you are a  
night
 owl who  
prefer
 to stay until late at  
night
, or you are a  
kind
 of person  
prefer
 to have pleasure with your  
own
 friends, or you are a  
kind
 of interested in having exact and deep  
knowledge
 about the  
place
 you travel to, traveling in a  
group
 led by a  
tour
 guide would  
makes
 you trouble in a way that you might not be able to  
make
  enough
 pleasure during your trip.
Doubtless,  
different
  people
 have  
different
  kinds
 of attitudes and behaviors. Actually, during a  
trip
 one may  
prefer
 to attend parties which  
being held
 late at  
night
, or  
prefer
 to go for a walk at midnight. An example from my  
own
 life may shed  
some
 light on this issue, I remember last year when I went to  
Kish
, which is a  
small
 island in Iran, and I had  
many
 difficulties during that  
trip
. Since I like to stay until late at  
night
, I found this  
trip
  very
 boring  
because
 most of the exciting parts of the  
tour
 programs were  
started
 in the mornings and I could not be able to attend them.
We should always remember that travelling with a  
group
 of your  
own
 friends is more enjoyable since most of the  
times
 you have  
many
 common interests with each other.  
Just
 imagine that you  
have to
 bear with a number of noisy  
people
 during a visit from a historical site, how this might be annoying for you distracting from the main points that the leader is making.  
Oppositely
, you may  
prefer
 to have  
a lot of
 fun during the  
trip
 and the  
group
 that you are traveling with is a  
kind
 of silent  
group
 in which no one speaks even a word. It is obvious that both situations are unfavorable.
Another side of the coin  
however
 is about the amount of  
knowledge
 that you wish to gain during your visit from a  
place
. Most of the  
times
 traveling in a  
group
 led by a  
tour
 guide  
is crowded
 by too  
many
  people
 and while the leader is describing about  
important
 issues you would not be able to pay attention. In this situation it is much better to study about the  
place
 you want to visit  
before
 the  
trip
 and deepen your  
knowledge
 about its historical  
places
 or its culture. By knowing a lot by yourself you definitely would find the  
trip
 more enjoyable.
To put it in a nut shell, from one who has difficulty arrange his  
time
 in a  
group
 activity or someone who do not enjoy spending  
time
 with strangers while traveling, and one whose purpose of traveling is to expand his  
knowledge
, travelling in a  
group
 may not be a favorable experience.  
So
 does not seem that choose  
some
 of your friends and plan to go to the  
trip
 with each other and  
make
 yourself  
highly
 informed about the  
place
 you wish to go is a better solution?