That's a good rate. The price for a double is a tad on the high side (but is presumably not for the lowest grade of room?) but presume you'd share that. HI Bloomsbury is coming in at about £140/night for a double for the same period, and that's one of my standby hotels (located close to Russell Square and Russell Square tube). I do think slightly more important then location is how close to good tube connections. You'll have to use tubes at some point, so ending the day with a short stagger between tube and hotel is always a plus.

However, I do doubt that you will find much better than that (short of pricelining, always a risk) for the standard of hotel you are getting for the strand. To get much cheaper, you'd have to drop a class - been there, done that, don't recommend it.