There are similarities and differences between Bissell 1161 Hard Floor Expert Deluxe Bagless Canister Vacuum and Bissell 1547 Hard Floor Expert Multi-Cyclonic Bagless Canister Vacuum Cleaner.
We will discuss them below.
Bissell 1547 vs 1161
images from manufacturer

Differences.

Power Control
The 1161 not only has a power button on the unit but also features fingertip control that you can turn on/off the vacuum on the handle.
While the 1547 only has the power button on the unit.

Suction Control
The 1161 features Variable Suction Control, it allows you to choose different suction levels.
While the 1547 uses the same suction level. But it has a air flow regulator that you can slide to open to reduce suction power, or close to get full suction power.

Dust Cup Capacity
The 1161 has 1L dust cup capacity versus 2L on the 1547.

Cyclonic Technology
The 1161 uses Cyclonic separation system whereas the 1547 uses Multi-Cyclonic separation system.

Amps
According to product specs on bissell.com, the 1161 uses 7 amps motor whereas the 1547 uses 7.3 amps motor.

Cord Length
The 1161 has a 17 ft. cord versus 20 ft. on the 1547.

Price
The Bissell 1161 is priced at $149.99 whereas the Bissell 1547 is priced at $169.99 on bissell.com

Similarities.
auto cord rewind system that allows you to rewind the cord with a push of the button;
Backed by 2 year limited warranty;
multi-level filtration;
bottom empty dust tank for easy emptying;
come with air driven hard floor tool with auto height adjustment, crevice tool, dusting tool, telescoping extension wand, and low pile carpet tool with a stationary brush ;

Download manuals to learn more.
Bissell 1161 manual
http://www.bissell.com/~/media/site%20us/documents/user%20guides/1161/bissell_user_guide_hard_floor_expert_deluxe_canister_vacuum_1161.pdf?la=en
Bissell 1547 manual
http://www.bissell.com/~/media/site%20us/documents/user%20guides/1547/bissell_user_guide_hard_floor_expert_multi_cyclonic_1547.pdf?la=en

Bissell 1154 vs 1161
images from manufacturer

Though they are very similar units, there is a big difference between Bissell 1161 Hard Floor Expert Deluxe Canister Vacuum and 1154 Hard Floor Expert Bagless Canister Vacuum – the wand handle.
The Bissell 1161 features the fingertip controls on the handle that allow you to adjust the suction power and turn on/off the vacuum cleaner whereas the Bissell 1154 does not have the fingertip controls, it only has the controls on the unit that the 1161 also has.
Due to the extra convenient feature, the 1161 is $20 more expensive than the 1154.
Another difference is the suction adjustment design on the unit.
And as you can see from the product pictures, they are in different colors.

If you know other difference between Bissell 1154 and 1161, please share below.

Similarities.
bagless;
corded;
5m long power cord;
automatic cord rewind system;
7 amps;
swivel steering feature;
air powered hard floor tool;
auto height adjustment;
variable suction controls;
rubber wheels with felt treads;
8 ft. flexible hose;
metal telescoping wand;
carry 2 year limited warranty;
cyclonic cleaning system;
multi-level filtration;
bottom empty tank;
1L dust cup capacity.

Download manuals to learn more.
Bissell 1154 Manual
http://www.bissell.com/~/media/site%20us/documents/user%20guides/1154/bissell_user_guide_hard_floor_expert_1154.pdf?la=en
Bissell 1161 Manual
http://www.bissell.com/~/media/site%20us/documents/user%20guides/1161/bissell_user_guide_hard_floor_expert_deluxe_canister_vacuum_1161.pdf?la=en