Unfortunately Tripadvisor doesn't provide the option to review tour operators so I have decided to share my experience here.
Abbott Travel, an Umrah Operator from London is one operator not to be used if you wish to have an enjoyable, trouble free umrah experience. You will be promised 4* hotels or hotels within short walking distance from the Haram, but you would be kept in 2* star hotels that are at least 10 minutes walk from the Haram. The hotel rooms are so cramped that you'll be lucky to find a space to open your suitcase and you'll be extremely lucky to find everything in working order. Broken lights, broken toilets/showers and dirty bed sheets are quite common and you could also find yourselves bitten by bed bugs. We had to pay the hotel staff from our pockets to have our bed sheets changed and bathroom cleaned.
It was very normal for the tour leader (company owner himself) to ask the group to be ready for a certain time to travel, yet he would himself turn up hours later while the group sat around wondering what was happening. At times, the coach booked was not large enough for the group so travelling would be delayed as he would then arrange a car for the rest of the people, but by then those who didn't get seats in the coach would be very angry and frustrated and this obviously ruined the mood of the whole group.
In order to make more profit (I'm assuming) the group leader makes changes to itinerary at the very last minute which mostly are very inconvenient for the group and when questioned about the changes, makes ridiculous excuses. If anyone argues against the changes, he becomes very intimidating by raising his voice regardless of who he's talking to.
I would definitely not go with him again.