Be very wary - niche is a dangerous word. If you haven't heard of smaller consultancies in your field then they may be very very small.I have experience of working with niche consultancies in transport, and it tends to be an old industry beardy who charges £600 a day for use of his experience so that he can spend half the year in Spain. Alternatively there are larger independent transport consultancies where you have more technical, smaller engagements where a big firm would be seen as too expensive.Again these are often run by an old industry beardy and you may find that the limited variety/scope of engagements is frustrating after big 4 work.Who do you work for now and who are you thinking of moving to?