7 Days in Siem Reap

I would say it mostly depends on your level of fitness. Angkor Wat is only about 30 minutes' easy ride from SR, and it's dead-flat (and beautiful countryside). Once you are there, most of your time will be walking (and climbing stairs) so it won't make much of a difference how you are ferried from site to site.

You won't have a guide, which will save you some money but you will miss out on some information. For myself (I bike 90 minutes a day through hilly San Francisco), the quiet (no engine noise, no yammering guide) would definitely be worth it.

I am not sure what the security situation is like, though. Maybe you should bring a U-lock.

The guys making the most money at Angkor are the truck drivers who collect exhausted, misguided but well meaning cycling enthusiasts and bring them and their bikes back to town. A trip out and back is no problem but when you add in all the widely spread out ruins, over 400 km squared, a motorbike is a better option. Too bad about the noise.

Even if your fitness level is moderate a day trip around the temples by bike should be doable and pleasant. It's dead flat, and you have plenty of temples to explore within the Angkor Archaeological Park. Your main challenge is the flat 7km ride to and from the park. If that doesn't intimidate you, you'll be all set. Usual custom is to rent cheap Chinese bikes for $1 a day. They are not real theft targets but you'll be provided with a cheap lock.

If you have 7 days I'd highly recommend getting out of Siem Reap for one to three days to visit remote temples - Preah Vihear, Banteay Chhmar or Preah Khan being the best options. Preah Vihear has plenty of accommodation nearby, including high-end accommodation. Banteay Chhmar has a laudable homestay program and gets almost zero visitors. A good place to observe the real Cambodia and hunt for temples lost in the jungle. Preah Khan had no accommodation nearby but can be combined with a trip to Sambor Prei Kuk, an important pre-Angkorian temple near Kompong Thom. Also very few visitors to either of these temples. Access to all of the above is easy these days - paved roads most or all of the way. You'd probably want to hire a private ride from Siem Reap to get to them, although with some pluck you can take public transport part of the way (then hire a moto for the last stretch to the temples proper).

If you've already booked 7 nights of accommodation in Siem Reap (a big mistake in July - hotels practically beg walk-in guests to occupy their rooms at drastically reduced rates in July), check now to see if you can cancel some some nights so you can get out of town a bit. It's a shame that most people feel the need to book accommodation months in advance these days. Not only do you generally get ripped off, but you also hem yourself into a rigid schedule with zero flexibility to take off for a few nights and explore alternative destinations.

I visited the temples close to one another (basically between Angkor Wat and Angkor Thom), by bicycle, it is magical and not hard, it's all flat terrain! For the more remote ones (those of the Rolous and Bantey Srei), I rented a motorbike. The only problem is to go to the booth where to buy the tickets ; it's relatively far from the temples on boring large roads, so what I did is take a moto-taxi the day before end of the afternoon, for visits the days after. Considering how fabulous is the whole area, the second time, I was on a motorbike (I did Phnom Penh-Siem Reap on it because at that time there was no motorbike erntal in SR) ; the road is so boring that I put the bike on a bus for the trip back to PP

Never understand why people say that this is a tough gig. Pretty straight forward - as mentioned, it's totally flat. Cheaper than having a yabbering guide with a two stroke engine blotting out the beautiful silence. And you can do what you want - one tip would be to visit the most popular temples at lunch time, when the tuk-tuk hordes are all having lunch. Just buy a good guide book - plenty available when you get there. Spent three days cycling around in March 2008. Magical.

Hilly San Francisco. Fitness. Here on the coastal plain of West Flanders a mole hill is about as much elevation as you will find. I will keep you posted when I get to Siem Reap, perhaps I shall just jump straight in.
Greetings, Homerus.

I booked 5 nights through agoda then 2 additional nights direct with the hotel and there was a difference in price.
I won't miss the money but would have preferred to have given it to the hotel In the first place.
I could head out of town for a night or two but I do not want to galavant around.
Greetings, Homerus.

Many parts of the hotel industry in Siem reap are part of a money laundering exercise for the Cambodian 'Generals'. Mainly the higher end places.